 \212 VF: ECG (see Figure 5.23 ): Use asynchronized DC shock (p. 731). See also the American Hear t Association ACLS Guidelines (p. 737). Ventricular extrasystoles (PVCS) are the most commo n post-MI arrhythmia but they are also seen in healthy people ( \211 10/h). Post-MI, they suggest elec- trical instability, and there is a risk of VF if the \200\234R on T \200 \235 pattern (i.e., no gap before the T wave) is seen. Specific therapies to decrease PVCs have been shown to increase mortality so only treat with -blockers. Otherwise, just obse rve patient and replace electrolytes. Torsade de pointes: Looks like VF but is VT with vary ing axis (ECG, see Figure 5.23 ). It is due to ^ QT interval (congenital, drug-induced, or biochemical) and also occurs post MI. Treatment : Mg sulfate overdrive pacing. Figure 5.22 Fusion and capture beats 126 Figure 5.23 Specimen rhythm strips (a) VT with a rate of 235/min. (b) VF. (c) Torsade de pointes tachycardia. Pacemakers Pacemakers supply electrical initiation to myocardial contraction. The pace- mak er lies subcutaneously, where it may be programed through the skin as necessary. Pacemakers usually last 7 \200\22315 yrs. See Table 5.7 for pacemaker terminology. Indications for te mporary cardiac pacing \212 \212 e n i c i d e m r a l u c s a v o d r a C Symptomatic bradycardia, unresponsive to atropine Acute conduction disturbances following M I: \212 After acute \200\223 Complete AV block \200\223 Mobitz type II AV block \200\223 Nonadja cent bifascicular or trifascicular block (p. 95) \200\223 After inferior MI, pacing may no t be needed in complete AV block if reasonably stable, rate is >40 \200\22350, and QRS comp lexes are narrow. anterior MI, prophylactic pacing is required in: i \212 \212 Suppression of drug-resistant tachyarrhythmias (e.g., SVT, VT) Special situations: During g eneral anesthesia, during cardiac surgery, dur- ing electrophysiological studies, drug over dose (e.g., digoxin, -blockers, verapamil). Indications for a permanent pacemaker \212 Complete AV block (Stokes \200\223Adams attacks, asymptomatic, congeni- tal) or Mobitz type II AV block (p. 120) with symptoms or HR <40 or >3 sec asystole Persistent AV block after anterior MI Symptomatic bradycardias (e.g., sick sinus syndrome [ Drug-resistant tachyarrhy thmias \212 \212 \212 Some say persistent bifascicular block after MI requires a permanent syst em: This remains controversial. Preoperative assessment: CBC, PT/PTT. Insert IV cannula. Ob tain consent for procedure under local anesthetic. Consider premedication. Give antibi- oti c coverage 20 min before, and 1 and 6 h after. Postprocedure assessment: Prior to discharge , check wound for bleeding or hematoma, check position on CXR, check pacemaker function. Du ring first week, inspect for wound hematoma, dehiscence, or muscle twitching. Count apical rate (p. 71): If this is \211 6 bpm less than the rate quoted for the pacemaker, suspect malfunction. Other problems: Lead fracture, pacemaker interference (e.g., from patient \200 \231s muscles). Types of pacemakers: Three-letter pacemaker codes enable the identification of the pacemaker: The first letter indicates the chamber paced (A = atria, V = ventricles, D = dual chamber); the second letter identifies the chamber sensed (A = atria, V = ventric les, D = dual chamber, 0 = none), and the third letter indicates the pacemaker response (T = triggered, I = inhibited, D = dual, R = reverse). DDD pacemakers are the only pacemakers that sense and pace both chambers. The fourth letter (if present) is for rate responsivenes s during motion. ECG of paced rhythm (ECG 7 [p. 99] and Figure 5.24 for rhythm strip): If t he system is on \200\234demand \200\235 of 60 bpm, a pacing spike will only be seen if the intrinsic heart rate is <60 bpm. If it is cutting in at a higher rate, its sensing mode is malfunctioning. If it is failing to cut in at slower rates, its pacing mode is malfunction ing(i.e., the lead may be dislodged, the pacing threshold is too high, or the lead [or insu lation] is faulty). If you see spikes but no capture (i.e., no systole), suspect dislodgmen t. p. 118]) 127 Table 5.7 Some confusing pacemaker terms Fusion beat: Union of native depolarization and pacemaker impulse. Pseudofusion: The pacema ker impulse occurs just after cardiac depolariza- tion, so it is ineffective, but it distor ts the QRS morphology. Pseudo pseudofusion beat: If a DVI pacemaker gives an atrial spike w ithin a native QRS complex, the atrial output is noncontributory. Pacemaker syndrome: In si ngle-chamber pacing, retrograde conduction to the atria, which then contract during ventric ular systole. This leads to retrograde flow in pulmonary veins and reduced cardiac output. Pacemaker tachycardia: In dual-chamber pacing, a short-circuit loop goes between the electr odes, causing an artificial WPW-like syndrome. Solution : Single-chamber pacing. Figure 5.24 ECG of paced rhythm. 128 Heart failure: Basic concepts Definition Heart failure occurs when the heart fails to maint ain the cardiac output and BP to meet the body \200\231s requirements. Prognosis is poor, w ith >50% of patients dying within 5 yrs of diagnosis. Classification LVF and RVF may occur independently, or together as con- gestive heart failure (CHF) . Low-output cardiac failure : The heart \200\231s output is inadequate (e.g., ejection fraction <0.35) or is only adequ ate with high filling pressures. Causes: Usually ischemia, hypertension, valve disorders, o r idiopathic. See Table 5.8 for the New York Heart Association (NYHA) clas- sification of h eart failure. \212Pump failure due to: \212Heart muscle disease: IHD, cardiomyopathy (p. 144). \212Restricted filling: Constrict ive pericarditis, tamponade, restrictive cardio- myopathy. This may be the mechanism of act ion of fluid overload: For constriction or tamponade, an expanding right heart impinges on the LV, so filling is restricted by the ungiving pericardium. For restriction, the heart is unable to expand properly because of intrinsic myocardial disease. \212Inadequate heart rate: -blockers, heart block, post MI \212Negative inotropic drug s: E.g., most antiarrhythmic agents \212Excessive preload: E.g., mitral regurgitation or fluid overload; fluid over- load may cause LVF in a normal heart if renal excretion is impaired or big volumes are involved (e.g ., IVI running too fast). More common if there is simultanous compromise of cardiac functio n and in the elderly. \212Chronic excessive afterload: E.g., AS, hypertension NB: High-output failure is rare. Here, output is normal or increased in the face of much in creased needs. Failure occurs when cardiac output fails to meet needs. It will occur with a normal heart, but even earlier if there is heart disease. Causes: Heart disease with anemi a or pregnancy, hyperthy- roidism, Paget \200\231s disease, arteriovenous malformation or f istulas, beriberi. Consequences : Initially features of RVF; later LVF becomes evident. Sym ptoms depend on which ventricle is more affected. LVF : Dyspnea, poor exercise tolerance, f atigue, orthopnea, paroxysmal nocturnal dys- pnea (PND), nocturnal cough ( pink frothy sp utum), wheeze (cardiac \200\234asthma \200\235), nocturia, cool peripheries, weight loss, muscle wasting. RVF : Peripheral edema (up to thighs, sacrum, abdominal wall), abdominal di s- tension (ascites), nausea, anorexia, facial engorgement, pulsation in neck and face (tri cuspid regurgitation), epistaxis. In addition, patients may be depressed or complain of dru g-related side effects. Signs The patient may look ill and exhausted, with cool peripher- i es and peripheral cyanosis. Pulse : Resting tachycardia, pulsus alternans. Systolic BP , narrow pulse pressure, JVP ^ . Precordium : Displaced apex (LV dilatation), RV heave (pulm onary hypertension). Auscultation : S 3 gallop (p. 51), murmurs of mitral or aortic valve d isease. Chest : Tachypnea, bibasal end-inspiratory crackles, wheeze ( \200\234cardiac asthm a \200\235), pleural effu- sions. Abdomen : Hepatomegaly (pulsatile in tricuspid regurgitat ion), ascites, peripheral edema. Investigations Blood tests: CBC, electrolytes, brain natri uretic peptide (BNP), TSH, iron studies. CXR : Cardiomegaly (cardiothoracic ratio >50%), pr ominent upper lobe veins (upper lobe diversion), peribronchial cuffing, diffuse interstitia l or alveolar shadowing, classical perihilar \200\234bat \200\231s wing \200\235 shadowing , fluid in the fissures, pleural effusions, Kerley B lines (variously attributed to interst itial edema and engorged peripheral lymphatics). ECG may indicate cause (look for evidence of ischemia, MI, or ventricular hypertrophy). It is rare to get a completely normal ECG in chronic heart failure. Echocardiography is the key investigation. It may indicate the cause (MI, valvular heart disease) and can confirm the presence or absence of LV dysfunction. En domyocardial biopsy is rarely needed but is occasionally helpful to diagnose the cause of r estrictive cardiomyopathies. e n i c i d e m r a l u c s a v o d r a C i 129 Table 5.8 New York classification of heart failure: Summary I II Comfortable at rest; dyspnea with ordinary activities III Dyspnea present with mild ac tivity IV Dyspnea present at rest or with minimal activity Heart disease present, but no dyspnea with ordinary activity Figure 5.25 The cxr in left ventricular failure (see also X-RAY PLATE 2) Dilated prominent upper lobe vessels Alveolar edema ( \200\230Bat \200\231s wings \200\231) Cardiomegaly Kerley B lines (interstitial edema) Pleural Effusion These features can be remembered as A, B, C, D, E . Heart failure: Management Acute heart failure is a medical emergency (p. 754). Chronic hear t failure Treat the cause (e.g., if arrhythmias; valve disease). \212 \212 130 Treat exacerbating factors (anemia, thyroid disease, infection, BP ^ ). Avoid exacerbating factors, such as NSAIDs (cause fluid retention, increase in afterload, and the effective ness of ACE-inhibitors). Stop smoking. Eat less salt. Maintain optimal weight and nutrition . Drugs: The following are used: 1 Diuretics: Loop diuretics routinely used to relieve symp toms (e.g., furo- semide; increase dose and frequency as necessary. SE: Mg , K + , re nal impairment. Monitor electrolytes and add K + -sparing diuretic (e.g., spironolactone ) if K + <3.2 mEq/L, predisposition to arrhythmias, concur- rent digoxin therapy (K + incr eases risk of digoxin toxicity), or preexist- ing K + -losing conditions. If refractory flu id, consider adding metolazone 5 mg/24 h PO prior to the furosemide dose. \212 \212 2 ace-inhibitor: Consider in all patients with left ventricular systolic dys- function; imp roves symptoms and prolongs life (see Table 5.9 ). If cough is a problem, an angiotensin re ceptor antagonist may be substituted (e.g., valsartan 40 \200\223160 mg/bid). 3 \222 -blockers (e.g., carvedilol, metoprolol XL). Recent randomized trials show that -blockers decrease mortality in heart failure. These benefits appear to be additive to thos e of ACE-inhibitor in patients with heart failure due to LV dysfunction. Should be initiate d after diuretic and ACE-inhibitor only if the patient is euvolemic. Use with caution : \200\234Start low and go slow \200\235; if in doubt seek specialist advice first. 4 Aldosterone antagonists: The RALES and EMPHASIS-HF trials have shown aldosterone antagoni sts) reduce mortality when added to conventional therapy. It should be initiated in NYHA I- IV patients. It improves endothelial dysfunction ( ^ nitric oxide bioactivity) and inhib- i ts vascular angiotensin I/angiotensin II conversion. Spironolactone is K + -sparing, and hy perkalemia should be monitored closely in the elderly or those with renal insufficiency. 5 Digoxin improves symptoms even in those with sinus rhythm (data from the RADIANCE and oth er trials). Use it if diuretics, ACE-inhibitor, and -blocker do not control symptoms, or in patients with AF. Dose : 0.125 \200\2230.25 mg/24 h PO. Monitor K + and maintain at 4 \200\2235 mEq/L. Other inotropes are unhelpful in terms of outcome. e n i c i d e m 6 Vasodilators: Long-acting nitrates reduce preload by causing venodilata- tion (e.g., isos orbide mononitrate 60 mg/24 h PO). Second-line agents include arterial vasodilators, which reduce afterload (e.g., hydralazine, SE: Drug-induced lupus) or -blockers, which are com bined arterial and venous vasodilators (e.g., prazosin). Vasodilators improve arte- rial he modynamics and reduce mortality (so especially valuable if ACE-inhibitor is contraindicated ). r a l u c s a v o d r a C i Intractable heart failure Reassess the cause. Is the patient taking his drugs? At maximum d ose? Is he compliant with diet? Admit to hospital for: \212 \212 \212 \212 \212 \212I n extremis , IV inotropes (p. 757) may be needed but will not prolong life Bed rest IV furosemide metolazone IV opiates and nitrates may relieve symptoms \200\224r arely used Daily weight and frequent electrolytes (K DVT prophylaxis: Heparin 5,000 U/12 h SC and TED stockings + ) (it may be difficult to wean patients off them). \212Consider \200\234tailoring therapy \200\235 with a right-heart catheterization. \212 Finally, consider a heart transplant or left ventricular assist device. How to start ACE-inhibitors See Table 5.9. 131 Table 5.9 How to start ACE-inhibitor Check that there are no contraindications/cautions: \212 \212 \212 \212 \212 \212 \212 \212 \212 Renal failure (serum creatinine >2.5 mg/dL; but not an absolute CI) Hyperkalemia: K Hyponat remia: Caution if <130 mEq/L (relates to a poorer prognosis) Hypovolemia Hypotension (systo lic BP <90 mm Hg) AS or LV outflow tract obstruction Pregnancy or lactation Severe COPD or cor pulmonale (not an absolute CI) Renal artery stenosis. 2 (Suspect if arteriopathic, e.g. , cerebrovascular dis- ease, IHD, peripheral vascular disease. ACE-inhibitors reduce glomer ular filtration rate (GFR) and may precipitate acute renal failure.) + >5.0 mEq/L Warn the patient about possible SE: \212 \212 \212 \212 \212 \212 \212 Hypotension Dry cough (1:10) Taste disturbance Hyperkalemia Renal impairment Urticaria and angioedema (<1:1,000) Rarely: Proteinuria, leukopenia, fatigue 2 If renovascular disease precludes the use of ACE-inhibitors, and furosemide is providing no answer, consider maximal vasodilatation with nitrates and hydralazine: seek expert advic e. (Continued) Table 5.9 (Continued) Starting ACE-inhibitors: Hypertensive patients can be safely started on ACE-inhibitors as o utpa- tients. Warn them about postural hypotension and advise them to take the first dose o n going to bed. Use a long-acting ACE-inhibitor at low doses. Patients with CHF are best st arted on ACE-inhibitors under close medi- cal supervision. Start with small dose and increa se every 2 wks until at target dose (equivalent of 40 mg lisinopril a day) or side effects supervene ( BP, ^ creatinine). Review in 1 wk for assessment; monitor CHEM 7 regularly. Patients on high doses of diuretics (>80 mg furosemide a day) may need a reduction in thei r diuretic dose first \200\224seek expert help. Hypertension Hypertension is a major risk factor for stroke and MI. It is usually asymp- to matic, so screening is vital. Defining hypertension BP has a skewed normal distribution wit hin the population and risk is continuously related to BP. Therefore, it is impossible to d efine \200\234hypertension. \200\235 We choose to select a value above which risk is signi ficantly elevated and the benefit of treatment is clear cut (see below). BP should be asses sed over a period of time (don \200\231t rely on a single reading). The \200\234observatio n \200\235 period depends on the BP and the presence of other risk factors or end-organ dam age. See Tables 5.10 and 5.11. Who to treat All patients with malignant hypertension or a s ustained pressure \211 140/90 mm Hg should be treated (p. 133). For those >140/90, the de cision depends on the risk of coronary events, presence of DM or end-organ damage (see the Joint National Committee Guidelines , [JNC VII]) . See also Table 5.12. Systolic or diastol ic pressure? For many years, diastolic pressure was consid- ered to be more important than systolic pressure. However, evidence from the Framingham and the MrFIT studies indicates th at systolic pressure is the most important determinant of cardiovascular risk in the over 5 0s. Systolic hypertension in the elderly: The age-related rise in systolic BP was considere d part of the \200\234normal \200\235 aging process, and isolated systolic hyper- tension (ISH) in the elderly was largely ignored. But evidence from major studies indicates, beyond doubt, that benefits of treating are even greater than treating moderate hypertension in m iddle-aged patients. \200\234Malignant \200\235 hypertension: This refers to severe hypert ension (e.g., systolic >200, diastolic >130mmHg) in conjunction with bilateral retinal hemo r- rhages and exudates; papilledema may or may not be present. Symptoms are common (e.g., h eadache visual disturbance). Alone, it requires urgent treatment. However, it may precip itate acute renal failure, heart failure, or encephalopathy, which are hypertensive emergen cies. Untreated, 90% die in 1 yr; treated, 70% survive 5 yrs. Pathological hallmark is fibr inoid necrosis. It is more common in younger patients and in black people. Look hard for an y underlying cause. Causes Essential hypertension (primary, cause unknown: 95% of cases. 132 Secondary hypertension: 5% of cases. Causes include: \212Renal disease: The most common s econdary cause. 75% are from intrinsic renal disease: Glomerulonephritis, polyarteritis nod osa (PAN), systemic sclerosis, chronic pyelonephritis, or polycystic kidneys. 25% are due t o renovascular disease, most frequently atheromatous (elderly male cigarette smokers, assoc iated peripheral vascular disease) or rarely fibromuscular dysplasia (young females)(p. 279 ). e n i c i d e m r a l u c s a v o d r a C \212Endocrine disease: Cushing \200\231s (p. 309) and Conn \200\231s syndromes (p. 313), pheochromocytoma (p. 315), acromegaly, hyperparathyroidism \212Others: Coarctation, pregnancy, steroids, MAOI Signs and symptoms Usually asymptomatic (except malignant hyperten- sion, above). Always examine the CVS system fully and check fo r retin- opathy. Are there features of an underlying cause (pheochromocytoma [p. 315]), sig ns of renal disease, radiofemoral delay, or weak femoral pulses (coarctation), renal bruits , palpable kidneys, or Cushing \200\231s syndrome? Look for end-organ damage: LVH, retinopa thy (Table 5.10) and proteinuria \200\224indi- cates severity and duration of hypertension and associated with a poorer prognosis. Investigations Basic: Electrolytes, creatinine, cho lesterol, glucose, ECG, urine analysis (for protein, blood). Specific (exclude a secondary cause): Renal ultrasound, renal arteriography, 24 h urinary VMA and metaneph- rines, urinar y free cortisol, renin, and aldosterone. ECHO and 24 h ambu- latory BP monitoring may be he lpful in some cases (e.g., white coat or borderline hypertension). i Table 5.10 Hypertensive retinopathy 133 Grade I Tortuous arteries with thick shiny walls (silver or copper wiring) II A \200\223V n icking (narrowing where arteries cross veins) III Flame hemorrhages and cotton wool spots I V Papilledema Figure 5.26 Seventh Report of the Joint National Committee on Prevention, Detection, Evalua tion, and Treatment of High Bp (jnc 7) 3 Algorithm for Treatment of Hypertension Measure BP and other risk factors (plasma lipids, glucose) SBP \211 160 and/or DBP 100 SBP <140 and DBP <90 SBP 140 \200\223159 and/or DBP 90 \200\22399 Lifestyle change + drugs if BP sustained at these levels on repeated measurements Reassess in 5yrs Give advice on healthy lifestyle CHD+ stroke risk* 20% over 10yrs or target organ damage or diabetes CHD+ stroke risk* <20% and no target organ damage Lifestyle and reassess every year Lifestyle and drug(s) if BP sustained on repeat measurements All values are mmHg; SBP=systolic; DBP=diastolic. 3 www.nhlbi.nih.gov/guidelines/hypertension/phycard.pdf Table 5.11 Classification of BP Category Normal SBP mm Hg <120 DBP mm Hg <80 and Prehypertension Hypertension, Stage 1 Hypertension, Stage 2 120 \200\223139 140 \200\223159 \211 160 or or or 80 \200\22389 90 \200\22399 \211 100 SBP, systolic BP; DBP, diastolic BP Table 5.12 Compelling indications for Individual Drug Classes Compelling indication \212 Initial therapy options THIAZ, BB, ACEI, ARB, ALDO ANT Heart failure \212 \212 \212 \212 \212 Post myocardial infarction High CVD risk Diabetes Chronic kidney disease Recurrent stroke p revention BB, ACEI, ALDO ANT THIAZ, BB, ACEI, CCB THIAZ, BB, ACEI, ARB, CCB ACEI, ARB THIAZ, ACEI 134 THIAZ, thiazide diuretic; ACEI, angiotensin converting enzyme inhibitor; ARB, angiotensin r ecep- tor blocker; BB, -blocker; CCB, calcium channel blocker; ALDO ANT, aldosterone ant agonist Hypertension: Management Look for and treat underlying causes (e.g., renal disease, acute p ain). Treatment goal For most patients, aim for BP <140/90, but 130/80 in patients with DM and renal disease. Reduce BP gradually; a rapid reduction can be fatal, especially in the c ontext of stroke. Lifestyle changes Reduce concomitant risk factors: Stop smoking; low-fat diet. Reduce alcohol and salt intake; increase exercise; reduce weight if obese. (See DASH diet; http://www.nhlbi.nih.gov/health/public/heart/hbp/ dash/new_dash.pdf.) Drugs Explain t he need for long-term treatment. Essential hypertension is not \200\234curable. \200\235 T he recent ALLHAT study suggests that adequate BP reduc- tion is more important than the spe cific drug used. However, ACE-inhibitor may provide additional renal benefit if coexisting DM is present. \212Thiazide diuretics are first choice, increasing the dose brings no bene fit and produces more SE: Hypokalemia, hyponatremia, postural hypoten- sion, impotence. \212 \222 -blockers: E.g., atenolol 50 mg/24 h PO. Higher doses provide little additional benefit. SE : Bronchospasm, heart failure, lethargy, impotence. CI : Asthma; caution in hea rt failure. \212ACE-inhibitor: E.g., lisinopril 2.5 \200\22320 mg/24 h PO (max 40 mg/d) or enal- april . ACE-inhibitor may be first choice if coexisting LVF, or in diabet- ics with microalbuminu ria or proteinuria. SE : Cough, K + ^ , renal failure, angioedema. CI : Renal artery stenos is, AS. \212Ca2+-channel antagonist: E.g., nifedipine SR 30 \200\22390 mg/24 h PO. SE: Flushing, fatigue, gum hyperplasia, ankle edema. Avoid short-acting drugs. \212Others: Angiotensin receptor antagonists (e.g., losartan), methyldopa (used in pregnan cy), and doxazosin (an -blocker). For refractory cases: Clonidine, minoxidil, or hydrala zine (causes a reflex tachycardia unless given with a -blocker and may cause an SLE-like syndrome). e n i c i d e m The four main classes of agent happen to start with ABCD. There is some evidence that in mo notherapy A&B are more effective in younger people and C&D in older individuals (and Africa n Americans). This may guide initial therapy, and if one drug fails, switch between groups. When add- ing drugs, it makes sense to combine A or B with C or D (e.g., a thi- azide and ACE-inhibitor, or -blocker and Ca 2+ \200\224channel antagonist) \200\224the \200\234A BCD rule. \200\235 Remember that most drugs take 4 \200\2238 wks to produce their maximum e ffect, so don \200\231t assess efficacy on the basis of a single clinic BP measurement. Mal ignant hypertension Most patients can be managed with oral ther- apy, except for those with encephalopathy. The aim is for a controlled reduction in BP over days, not hours. Avoid su dden drops in BP as cerebral autoregulation is poor (so stroke risk ^ ). \212 r a l u c s a v o d r a C i Bed rest; start a loop diuretic (e.g., furosemide 40 \200\22380 mg daily a thiaz- ide). There is no ideal antihypertensive therapy, but labetalol, atenolol, or long-acting calcium blockers may be used orally. Encephalopathy (headache, focal CNS signs, seizures, coma): A im to reduce BP to 110 mm Hg diastolic over 4 h. Admit to monitored area. Insert intra-art erial line for pressure monitoring. Furosemide 40 \200\22380 mg IV; then either IV labetalo l (e.g., 50 mg IV over 1 min, repeated every 5 min, max 200 mg) or sodium nitroprusside inf usion (0.5 mcg/kg/min IVI titrated up to 8 mcg/kg/min, e.g., 50 mg in 1L dextrose 5%; expec t to give 100 \200\223200 mL/h for a few days at most to avoid cyanide risk). Labetalol or hydralazine can also be used intravenously. Avoid hydralazine if CAD. Never use sublingual (SL) nifedipine to reduce BP (it can cause an uncon- trollable drop in BP and stroke). \212 135 1 3 6 Figure 5.27 ECG 8: Left ventricular hypertrophy \200\224this is from a patient with maligna nt hypertension \200\224note the sum of the S-wave in V 2 and R-wave in V 6 is >35 mm. aVR I V1 V4 V2 V5 aVL 11 V3 V6 111 aVF 11 Rheumatic fever This systemic infection is still common in the Third World, although increa singly rare in the West. Peak incidence : 5 \200\22315 yrs. Tends to recur unless prevented . Pharyngeal infection with Lancefield Group A -hemolytic strep- tococci triggers rheuma tic fever 2 \200\2234 wks later, in the susceptible 2% of the population. An antibody to th e carbohydrate cell wall of the streptococcus cross-reacts with valve tissue (antigenic mim icry) and may cause permanent damage to the heart valves. Diagnosis Use the revised Jones c riteria . There must be evidence of recent strep infection plus two major criteria, or one major + two minor. Evidence of streptococcal infection: \212 Recent streptococcal infectio n \212 History of scarlet fever \212 +ve throat swab \212 Elevated in antistreptolysin O titer ASOT >200 U/mL \212 Elevated in DNase B titer Major criteria: \212Carditis: Tachyc ardia, murmurs (mitral or AR, mid diastolic murmur [mid diastolic, p. 53]), pericardial rub , CCF, cardiomegaly, conduction defects (45 \200\22370%). An apical systolic murmur may be the only sign. e n i c i d e m r a l u c s a v o d r a C i \212Arthritis: A migratory arthritis; usually affects the larger joints (75%) \212Subcuta neous nodules: Small, mobile painless nodules on extensor surfaces of joints and spine (2 \200\22320%) \212Erythema marginatum: Geographical-type rash with red, raised edges and 137 clear center; occurs mainly on trunk, thighs, arms in 2 \200\22310% \212Sydenham \200\231s chorea (St. Vitus \200\231 dance): Occurs late in 10%. Unilateral o r bilateral involuntary semipurposeful movements; may be preceded by emotional lability and uncharacteristic behavior Minor criteria: \212 \212 \212 \212 \212 Management \212 Penicillin G 0.6 \200\2231.2 million units IM stat then penicillin V 250 mg/6 h PO \212Analgesia for carditis/arthriti s : Aspirin 100 mg/kg/d PO in divided doses (maximum 8 g/d) for 2 d, then 70 mg/kg/d for 6 wks. Monitor salicy- late level. Toxicity causes tinnitus, hyperventilation, metabolic acid osis. Alternative : NSAIDS. Steroids are thought not to have a major impact on sequelae, bu t they may improve symptoms. Immobilize joints in severe arthritis. Diazepam for the chorea Fever Raised ESR or CRP Arthralgia (but not if arthritis is one of the major criteria) Prol onged P \200\223R interval (but not if carditis is major criterion) Previous rheumatic feve r \212 \212 \212 Prognosis 60% with carditis develop chronic rheumatic heart disease. This corre lates with the severity of the carditis. Acute attacks last an average of 3 months. Recurre nce may be precipitated by further streptococcal infec- tions, pregnancy, or use of oral co ntraceptives. Cardiac sequelae affect mitral (70%), aortic (40%), tricuspid (10%), and pulm onary (2%) valves. Incompetent lesions develop during the attack, stenoses years later. Sec ondary prophylaxis Penicillin V 250 mg/12 h PO until no longer at risk (>30 yrs). Thereafte r, give antibiotic prophylaxis for dental or other surgery (p. 143). Erythromycin can be us ed if penicillin allergic. Mitral valve disease Mitral stenosis Causes: Rheumatic; congenital, mucopolysaccharidoses, endocardial fibroelastosis, malignant carcinoid, prosthetic valve. Presentation: Dyspnea, f atigue, palpitations, chest pain, systemic emboli, hemoptysis, chronic bronchitis-like pict ure complications (below). Signs : Malar (i.e., cheek) flush; low-volume pulse; AF commo n; tapping, undisplaced, apex beat (palpable S 1 ). On auscultation : Loud S 1 ; opening sn ap (pliable valve); rumbling mid-diastolic murmur (heard best in expiration, as the patient lies on their left side). Graham Steell murmur (early diastolic, p. 53) may occur. Severit y: The more severe the stenosis, the longer the diastolic murmur, and the closer the openin g snap is to S 2 . Tests : ECG: AF; P-mitrale if in sinus rhythm; RVH; progressive RAD. CXR : Left atrial enlargement; pulmonary edema; mitral valve calcification. Echocardiography is diagnostic. Significant stenosis exists if the valve orifice is <1 cm 2 /m 2 body sur- fac e area. Indications for cardiac catheterization: Previous valvotomy, signs of other valve d isease, angina, severe pulmonary hypertension, calcified mitral valve. Management: If in AF , rate control is crucial (add a -blocker or calcium channel blocker if needed to keep t he pulse rate <90); anticoagulate with warfarin. Diuretics reduce preload and pulmonary ven ous congestion. If this fails to control symptoms, balloon valvuloplasty (if pliable, nonca lcified valve), open mitral valvotomy, or valve replacement. SBE/IE, prophylaxis for dental or surgical procedures (p. 143). Oral penicillin as prophylaxis against recurrent rheumati c fever if <30 yrs old. Complications: Pulmonary hypertension; emboli, pressure from large LA on local structures; e.g., hoarseness (recurrent laryngeal nerve), dysphagia (esophagus) , bronchial obstruction, infective endocarditis (rare). Mitral regurgitation Causes: Functi onal (LV dilatation); annular calcifica- tion (elderly); rheumatic fever, infective endocar ditis, mitral valve prolapse, ruptured chordae tendinea; papillary muscle dysfunction/ruptu re; connec- tive tissue disorders (Ehlers \200\223Danlos, Marfan \200\231s); cardiomyopathy ; congenital (may be associated with other defects, e.g., atrial septal defect [ASD], AV ca nal); appetite suppressants (e.g., fenfluramine, phentermine). Symptoms: Dyspnea, fatigue, palpitations, infective endocarditis. Signs: AF; displaced, hyperdynamic apex; RV heave; so ft S 1 ; split S 2 ; loud P 2 (pulmo- nary hypertension) pansystolic murmur at apex radiati ng to axilla. Severity: The more severe, the larger the left ventricle. Tests: ECG: AF P -mitrale if in sinus rhythm (may mean left atrial size ^ , LVH. CXR: Big LA and LV, mitral valve calcification, pulmonary edema. Echocardiogram to assess LV function (trans-esophagea l to assess severity and suitability for repair rather than replacement). Doppler echo to a ssess size and site of regurgitant jet. Cardiac catheterization to confirm diagnosis, exclu de other valve disease, assess coronary artery disease. Management: Digoxin for fast AF. An ticoagulate if AF, history of embolism, prosthetic valve, additional mitral stenosis. Diure tics improve symptoms. Surgery for deteriorating symptoms; aim to repair or replace the val ve before LV irreversibly impaired. Antibiotics to prevent endocarditis. Mitral valve prola pse Prevalence : 5%. Occurs alone or with: ASD, patent ductus arteriosus, cardiomyopathy, Turner \200\231s syndrome, Marfan \200\231s syndrome, osteogenesis imperfecta, pseudoxantho ma elasticum, WPW (p. 121). Symptoms: Asymptomatic \200\224or atypical chest pain and palpi ta- tions. Signs: Mid-systolic click and/or a late systolic murmur. Complications: Mitral r egurgitation, cerebral emboli, arrhythmias, sudden death. Tests: Echocardiography is diagno stic. ECG may show inferior T wave inversion. Treatment: -blockers may help palpitations and chest pain. Give endocardi- tis prophylaxis (p. 143) if coexisting mitral regurgitatio n. 138 Aortic valve disease Aortic stenosis (AS) Causes: Senile calcification is the commonest. Al so congenital bicuspid valve. Presentation: Angina, dyspnea, dizziness, syncope, systemic e mboli if infec- tive endocarditis, CCF, sudden death. Signs : Slow rising pulse with narrow pulse pressure (feel for diminished and delayed carotid upstroke \200\224 \200\234parvus e t tardus \200\235); heaving, undisplaced apex beat; LV heave; aortic thrill; ejection systo lic murmur (heard at the base, left sternal edge and the aortic area; radiates to the carot ids). As stenosis worsens, A 2 is increasingly delayed, giving first a single S 2 and then reversed splitting. But this sign is rare. More common is a quiet A 2 . In severe AS, A 2 m ay be inaudible (calcified valve). There may be an ejection click (pliable valve) or an aud ible S 4 (said to occur more commonly with bicuspid valves, but not in all populations). Te sts: ECG: P-mitrale, LVH with strain pattern; LAD (left anterior hemi- block); poor R wave progression; LBBB or complete AV block (calcified ring). CXR: LVH; calcified aortic valve; poststenotic dilatation of ascending aorta. Echo is diagnostic (p. 104). Doppler echo can e stimate the gradient across valves: Severe stenosis if gradient >50 mm Hg and valve area <0 .5 cm 2 . If the aortic jet velocity is >4 m/sec (or is ^ by >0.3 m/sec per year) risk of c omplications is increased. Cardiac catheter can assess valve gradient, LV function, coronar y artery disease, the aortic root. Differential diagnosis: HOCM. Management: Symptomatic pa tients have a poor prognosis: 2 \200\2233-yr survival if angina/syncope; 1 \200\2232-yr sur vival with cardiac failure. Prompt valve replace- ment (p. 140) is recommended. In asymptom atic patients with severe AS and a deteriorating ECG, valve replacement is also recommended . If the patient is not medically fit for surgery, percutaneous valvuloplasty may be attemp ted. Endocarditis prophylaxis (p. 143). Percutaneous valve replace- ment is still experimen tal but may be approved soon. Aortic sclerosis is senile degeneration of the valve. There i s an ejection systolic murmur, no carotid radiation, and a normal pulse and S 2 . Aortic re gurgitation (ar) Causes : Congenital valve disease : Rheumatic fever, infective endocarditi s, rheumatoid arthritis, SLE, pseudoxanthoma elasticum, appetite suppressants (e.g., fenflu ramine, phentermine). Aortic root disease: Hypertension, trauma, aortic dissection, seroneg ative spon- dyloarthritis (ankylosing spondylitis, reactive arthritis, psoriatic arthritis) , Marfan \200\231s syndrome, osteogenesis imperfecta, syphilitic aortitis. Symptoms: Dyspne a, palpitations, cardiac Signs: Collapsing (water-hammer) pulse, wide pulse pressure, displ aced, hyperdynamic apex beat, high-pitched early diastolic murmur (heard best in expiration , with patient sitting forward). Associated signs: Corrigan \200\231s sign (carotid pulsa- tion), Quincke \200\231s sign (capillary pulsations in nail beds), Duroziez \200\231s sign (femoral diastolic murmur as blood flows backwards in diastole), Traube \200\231s sign ( \200\234pistol shot \200\235 sound over femoral arteries). In severe AR, an Austin Flint mu rmur may be heard (p. 53). Investigations: ECG: LVH. CXR: Cardiomegaly, dilated ascending a orta, pul- monary edema. Echocardiography is diagnostic. Cardiac catheterization to assess severity of lesion, anatomy of aortic root, LV function, coronary artery disease, other val ve disease. Management: Indications for surgery: ^ Symptoms, enlarging heart on CXR/echo, E CG deterioration (T wave inversion in lateral leads), infective endocarditis refractory to medical therapy. Aim to replace the valve before significant LV dysfunction occurs. Endocar ditis prophylaxis (p. 143). e n i c i d e m r a l u c s a v o d r a C i 139 failure. Right-heart valve disease Tricuspid regurgitation Causes : Pulmonary hypertension, rheumati c fever, infective endocarditis (IV drug abusers), carcinoid syndrome, con- genital (e.g., ASD, AV canal, Ebstein \200\231s anomaly). Symptoms: Fatigue, hepatic pain on exertion, asc ites; edema. Signs: Giant v waves and prominent y descent in JVP (p. 49); RV heave; pansyst olic mur- mur, heard best at lower sternal edge in inspiration; pulsatile hepatomegaly; jau ndice; ascites. Management: Treat underlying cause. Drugs : Diuretics, digoxin, ACE-inhibit ors. Valve replacement (20% operative mortality). Tricuspid stenosis Causes: Rheumatic feve r; almost always occurs with mitral or aortic valve disease. Symptoms: Fatigue, ascites, ed ema. Signs: Giant a wave and slow y descent in JVP (p. 49); opening snap, early diastolic m ur- mur heard at the left sternal edge in inspiration. Diagnosis: Doppler echo. Treatment: Diuretics; surgical repair. Pulmonary stenosis Causes : Usually congenital (Turner \200\231 s syndrome, Noonan \200\231s syndrome, William \200\231s syndrome, Fallot \200\231s tetralo gy, rubella). Acquired causes : Rheumatic fever, carcinoid syndrome. Symptoms: Dyspnea, fat igue, edema, ascites. Signs: Dysmorphic facies (congenital causes); promi- nent a wave in J VP; RV heave. In mild stenosis, there is an ejection click, ejection systolic murmur (which radiates to the left shoulder); widely split S 2 . In severe stenosis, the murmur becomes longer and obscures A 2 . P 2 becomes softer and may be inaudible. Tests: ECG: RAD, P-pulmo nale, RVH, RBBB. CXR : Poststenotic dilatation of pulmonary artery; RV hypertrophy; right a trial hypertrophy. Cardiac catheterization is diagnostic. Treatment: Pulmonary valvuloplast y or valvotomy. Pulmonary regurgitation is caused by any cause of pulmonary hyper- tension (p. 195). A decrescendo murmur is heard in early diastole at the left sternal edge (the Gra ham Steell murmur). 140 Cardiac surgery Valvuloplasty can be used in mitral or pulmonary stenosis (pliable, non- ca lcified valve, no regurgitation). A balloon catheter is inserted across the valve and infla ted. Valvotomy Closed valvotomy is rarely performed now. Open valvotomy is performed under cardiopulmonary bypass through a median sternotomy. Valve replacements Mechanical valves ma y be of the ball-cage (Starr \200\223 Edwards), tilting disc (Bj rk \200\223Shiley), or double tilting disc (St. Jude) type. These valves are very durable but the risk of thromboe mbolism is high; patients require lifelong anticoagulation. Xenografts are made from por- c ine valves or pericardium. These valves are less durable and may require replacement at 8 \200\22310 yrs. Anticoagulation is not required unless there is AF. Homografts are cadaveri c valves. They are particularly useful in young patients and in the replacement of infected valves. Complications of pros- thetic valves : Systemic embolism, infective endocarditis, hemolysis, struc- tural valve failure, arrhythmias. CABG see Table 5.13. Cardiac transplant ation Consider this when cardiac disease is severely curtailing quality of life and surviva l is not expected beyond 6 \200\22312 months. Refer to a specialty center. Main contraindic ations: Malignancy, age >70, significant peripheral or cerebrovascular disease, DM with end -organ dys- function, noncompliance. e n i c i d e m Table 5.13 Coronary artery bypass grafts Indications for cabg: To improve survival \212 \212 Left main disease Triple vessel disease involving proximal part of the left anterior descen ding, especially with LV dysfunction