Valvular cardiomyopathy Patients with valvular heart disease will develop a cardiomyopathy that is dependent on the predominant valvular lesion. Signi \201 cant improvement in cardi ac function can often be seen after correction of the valve disease. Hypertensive cardiomyopathy Hypertension causes LVH in response to increased afterload, whi ch is compensatory and protective to a point. However, there are ultimately det- rimental e ffects on systolic and diastolic ventricular function. Hypertension also leads to accelerat ed atherosclerosis and ischaemic heart disease. Hypertensive cardiomyopathy is the commones t form of CCF outside the western world. Alcoholic cardiomyopathy Chronic alcohol excess is the commonest 2 cause of DCM in the w estern world. Proposed mechanisms include (1) a direct toxic effect of ethanol causing apop tosis and myocyte loss and acetyldehyde causing depressed myocardial contraction; (2) conco mitant nutritional de \201 ciencies (especially thiamine); and (3) rarely, toxic effects o f additives (cobalt). Progression to alcoholic cardiomyopathy is related to the mean daily alcohol intake and total duration of drinking (approximately 1 L of wine every day for 5 ye ars). Clinical presentation, diagnosis, and treatment are similar to DCM. However, unlike o ther forms of DCM, abstinence from alcohol early in the disease process may stop progressio n, or even result in signi \201 cant improvement in cardiac function. PERIPARTUM CARDIOMYOPATHY 447 Metabolic cardiomyopathy Various abnormalities in metabolism can result in cardiomyopathy. As already mentioned, lysosomal and glycogen storage diseases can cause a form of restricti ve cardiomyopathy. Haemochromatosis also causes restrictive cardiomyopathy by unknown mecha nisms. Acquired errors of metabolism such as acromegaly result in biventricular hypertrophy . Diabetes mellitus can cause cardiomyopathy with systolic and/or diastolic dysfunction, ev en in the absence of signi \201 cant epicardial CAD. Takotsubo cardiomyopathy Takotsubo cardiomyopathy, also known as stress-induced cardiomyop- athy, or transient apical ballooning syndrome, is a rare but increasingly recognized cardi ac syndrome. It is characterized by transient systolic dysfunction of the apical and/or mid segments of the left ventricle, with a compensatory hyperkinesis of the basal walls produc ing ballooning of the apex during systole. The condition is more prevalent in postmeno- pau sal women and is often triggered by intense emotional or physical stress (e.g. bereavement, domestic abuse, natural disasters). The clinical presentation of takotsubo cardiomyopathy is similar to acute MI, with retroste rnal chest pain, ST segment elevation and raised cardiac biomarkers. Other features may inc lude tachy- and bradyarrhythmias, signs of left ventricular failure, transient LVOT obstruc tion, and even cardiogenic shock. Coronary angiography, by de \201 nition, reveals no evid ence of signi \201 cant coronary stenosis. The diagnosis is reached by left ventriculograp hy or transthoracic echocardiography (TTE), which identi \201 es the characteristic apical ballooning with associated reduced left ventricular systolic function. The pathogenesis of takotsubo cardiomyopathy remains poorly understood; however, postulated mechanisms include catecholamine excess causing coronary artery spasm and microvascular dysfunction, or by di rect catecholamine-mediated myocardial toxicity. Management of this condition is essentially supportive, with IV hydration, treatment of com plications, and attempts to alleviate any causative emotional or physical stress. The progn osis, in small studies, is good in those individuals surviving the acute episode, with reco very of normal left ventricular function within 4 \200\2236 weeks. Peripartum cardiomyopathy Peripartum cardiomyopathy is a form of DCM. Symptoms occur in the third trimester and the diagnosis is made in the peripartal period. Approximately half wil l show complete or near-complete resolution over the \201 rst 6 months post-partum. Of th e remainder, some will continue to deteriorate and result in death or transplantation, whil e others continue to experience chronic CCF. Its diagnosis is established by excluding othe r causes of DCM, and the cause is unknown (also see b Chapter 15, Heart disease in pregnanc y, p. 673). 448 CHAPTER 8 Heart muscle diseases Cardiomyopathy in systemic disease Systemic lupus erythematosus (SLE) can cause heart disea se in many ways. Approximately 10 % of patients with SLE have evidence of myocar- ditis. Pa tients with associated antiphospholipid antibody syndrome have increased risk of valvular a bnormalities and DCM due to thrombotic occlusions of the microcirculation without vasculiti s. They also have increased atherogenesis. Pulmonary hypertension due to pulmonary vasculitis is an uncommon cause of cardiomyopathy i n patients with rheumatoid arthritis (see also b p. 618). Nutritional cardiomyopathy Thiamine is an important coenzyme in the hexose monophophate shu nt. Infants who are breast-fed in areas with diets de \201 cient in thiamine develop mainl y right ventricular failure between 1 and 4 months of age. Prompt correction of the vitamin de \201 ciency results in rapid improvement in the cardiac abnormalities without long-ter m consequence. Protein \200\223calorie malnutrition (marasmus, kwashiorkor) results in thinning and atroph y of muscle \201 bres and ultimately DCM. Careful treatment may result in marked improvem ent over several months, provided the patient survives the initial period (see also b Chapt er 14, Cardiovascular disease in less-developed countries, p. 653). Sensitivity or toxic reactions A large number of non-infectious agents can damage the myoca rdium. The damage can be acute, with evidence of an in \202 ammatory reaction, or there ma y be no in \202 ammation and necrosis as in hypersensitivity reac- tions. Other agents lea d to chronic changes, with progressive \201 brosis and an ultimate picture similar to DCM . Numerous chemical and industrial agents, radiation, and excessive heat can all cause myoc ardial damage. Neuromuscular disorders Cardiac involvement in Friedreich \200\231s ataxia is relatively co mmon, although usually asymptomatic. Friedreich \200\231s ataxia is an autosomal recessive trait with loss of function of the frataxin gene. Clinical manifestations include progressi ve ataxia of all four limbs, diabetes mellitus, and cardiac disease. It is most commonly as sociated with HCM on electrocardiography and echocardiography but is distinct from the gene tic variety by lack of myo \201 - brillar disarray on histology. Serious ventricular arrhy thmias and complica- tions related to cardiomyopathy are the most frequent cause of morbidi ty. Rarely, it is associated with DCM. This page intentionally left blank 450 CHAPTER 8 Heart muscle diseases Muscular dystrophies Muscular dystrophies (MDs) are a group of hereditary muscle disorders characterized by progressive skeletal muscle weakness. Over 100 condi- tions are associated with a muscular dystrophy, although the best charac- terized include Duchenne \200\231s an d Becker \200\231s, limb-girdle, facioscapulohumeral, myotonic, oculo-pharyngeal, distal, a nd Emery \200\223Dreifuss. A signi \201 cant number of types of muscular dystrophy are multisystem disorders, with ef fects on smooth muscle and cardiac muscle as well as skeletal muscle. The MDs can be inheri ted with an autosomal dominant, autosomal recessive, or X-linked pattern of inheritance. Th ey affect the myocardium and conduction tissue predominantly, causing varying degrees of he art block, tachyarrhythmias, and heart failure. Symptoms can be very dif \201 cult to gauge, as affected patients are often limited by sev ere disability. Regular surveillance with 12-lead ECG, in the \201 rst instance, and a lo w threshold for echocardiography is important to identify cardiac involvement early. Once a diagnosis of cardiomyopathy is made, standard heart failure treatment with diuretics, ACE- Is, and B -blockers is required. Arrhythmias and symptoms of CCF secondary to DCM are a sig ni \201 cant cause of morbidity and mortality in this group of patients. Duchenne \200\231s (DMD) and Becker \200\231s (BMD) muscular dystrophy are X-linked disorde rs of the dystrophin gene. DMD presents in childhood and is the commonest hereditary MD, wi th near-complete absence of the sarcolemmal membrane protein dystrophin. BMD presents in ad ulthood and is associated with less-severe skeletal muscle involvement but often more-sever e cardiac muscle involvement. Cardiac abnormalities include conduction abnormalities of the AV node, and LV dysfunction that can be rapidly progressive. Limb girdle muscular dystrophy (LGMD) affects the shoulder and pelvic girdle muscles and ca n be inherited in an autosomal dominant or recessive pattern. Mutations occur in genes enco ding proteins of the nuclear envelope in skeletal muscle. Cardiac involvement is particular ly predominant in LGMD1B (laminopathy), LGMD1D, LGMD2E, and LGMD2I, with cardiomyopathy and conduction-system disease. Facioscapulohumeral muscular dystrophy (FSH) is an autosomal dominant MD with progressive i nvolvement of the facial, shoulder, and hip girdle muscles. Cardiac manifestations include P-wave abnormalities, interventricular conduction delay, and supraventricular arrhythmias. Myotonic dystrophy is an autosomal dominant multisystem disease caused by a trinucleotide r epeat defect in the gene encoding myotonin. It is associated with AV conduction abnormaliti es, atrial and ventricular arrhythmias, and rather than cardiomyopathy in 710 % of cases. S CD from any cause is seen in up to 30 % of patients with myotonic dystrophy. MUSCULAR DYSTROPHIES 451 Emery \200\223Dreifuss MD has a variable pattern of inheritance and is caused by mutations in lamin A and lamin C (nuclear envelope proteins). Muscle weakness has a humeral and peron eal distribution, with multiple contractures often being a feature. Cardiac manifestations include AV conduction abnormalities and atrial arrhythmias. SCD due to ventricular tachyarr hythmia can occur. 452 CHAPTER 8 Heart muscle diseases Myocarditis Myocarditis is the process whereby the myocardium becomes in \202 amed by one of a large range of infectious agents. Unfortunately, the infectious agent is rarely identi \201 ed. Numerous bacteria, viruses, spirochetes, fungi, parasites, and rickettsia can ca use myocarditis. Etiology Damage can result from a number of mechanisms, including a direct toxic effect on the myocyte, production of a toxin (e.g. diphtheria), and immunologically mediated cell dam age. Histological \201 ndings depend on a number of factors, including the infectious age nt, stage of disease, and mechanism of damage. Damage can be focal or diffuse, and is rando mly distributed throughout the myocardium. Symptoms The clinical consequences of the damage can range from asymptomatic subclinical in fection to rapidly progressive and ultimately fatal CCF. Long-term consequences are also variable. Patients who were initially asymptomatic can pres ent after a prolonged latency period with DCM or have complete recovery. Patients who prese nt early, even with fulminant CCF, can also have complete recovery. Patients with non-fulmi nant presentations can gradually deteriorate or recover gradually. Diagnosis The diagnosis is often established by identifying the associated systemic illness . Isolation of the infectious agent is rarely achieved, although clearly supportive of the diagnosis if positive. Endomyocardial biopsy can be useful in con \201 rming the diagnosis but is frequently negative. Treatment Management of patients with myocarditis is largely supportive. Physical activity should be restricted, as in animal models exercise was found to be detrimental to cardiac f unction. Standard management of CCF and eradica- tion of the infectious agent are the mains tay of treatment. Symptomatic arrhythmias should be controlled, and B -blockers may be card ioprotective. Trials of immunosuppressive therapy in patients with myocarditis have been la rgely disappointing. The use of steroids in acutely ill patients could be considered but an y bene \201 t is unproven. RICKETTSIAL MYOCARDITIS 453 Viral myocarditis \200 In western countries, the enterovirus (especially Coxsackie B) is the commonest cause of myocarditis. This is usually mild and self-limiting, although it can be particularly virulent in neonates and young children. Clinical manifestations in adults include myalgia, pleuritic chest pains, upper respiratory tract symptoms, arthralgia, palp itations, and fever. The ECG is usually abnormal with ST- and T-wave changes, VEs, and AV c onduction abnormalities. Cardiac enzymes may be elevated or normal, re \202 ecting the deg ree of myocardial necrosis. Echocardiography may show diffuse or regional LV dysfunction. M ost make an uneventful recovery within weeks. Treatment is symptomatic. Other viruses such as cytomegalovirus (CMV), Dengue, hepatitis, Epstein \200\223Barr virus (EBV), in \202 uenza, and varicella are rarely associated with cardiac involvement. ECG changes and cardiac enzyme release makes the diagnosis. With mumps , myocarditis is rarely recognized, but pathologically, it is common. Myocarditis generally occurs in the \201 rst week of illness and is transient. Rubella infection in the 1st tr imester of pregnancy results in congenital lesions such as patent ductus or pulmonary arter y maldevelopment; myocarditis is rare but causes fetal/ neonatal heart failure. Cardiac involvement is common in patients with human immunode \201 ciency virus (HIV; up to 50 % ) but only clinical evident in 10 % . The usua l presentation is with CCF and DCM, due to a direct effect of HIV on the myocardium, althou gh opportunistic infection in acquired immune de \201 ciency syndrome (AIDS) patients is a nother important cause of myocarditis (see also b HIV and the cardiovascular system, p. 658 ). Rickettsial myocarditis \200 Q fever ( R. burnetti ) typically causes endocarditis; peric arditis (chest pain and dyspnoea) is also common. Myocarditis is uncommon and produces ECG changes such as transient ST- and T-wave changes). \200 Rocky Mountain spotted fever ( R. rickettsii ) produces a widespread vasculitis that involves the myocardium. ECHO shows unexpected LV dysfunction, which may pe rsist even after the infection is cleared. \200 Scrub typhus ( T. rsutsugamushi ) produce s a panvasculitis that may involve the myocardium, producing hemorrhage into the myocardium and subepicardial petichia e. Long-term damage appears to be infrequent. 454 CHAPTER 8 Heart muscle diseases Bacterial myocarditis \200 Diphtheria : myocarditis occurs in up to 20 % and is due to th e production of a toxin that inhibits protein synthesis. Clinical signs appear towards the en d of the \201 rst week of infection with CCF, and cardiomegaly. ECG changes are seen and may persist after recovery. Treatment with antitoxin should be given early in the course of the disease. Corticosteroids do not appear to be helpful. However, treatment with carnitin e seems to reduce the incidence of heart failure and need for pacemaker, and lowers mortali ty. Meningococcus : myocarditis is associated with increased mortality, and results in haemorrh agic lesions and intracellular organisms. Clinical features include CCF and an pericardial effusion with tamponade. Patients with septicaemia should be monitored, especially if there are ECG abnormalities. Mycoplasma : ECG changes are not uncommon in patients with mycoplasma pneumonia. Other manifestations include pericarditis and CCF. No speci \201 c t reatment for the carditis is usually indicated. Whipple \200\231s disease: ( Tropheryma whippelli ) may involve the myocardium with in \201 ltration with periodic acid \200\223Schiff (PAS)-positive macrophages. Coronary artery lesions may be seen. Pulmonary arterial hypertension can occur. Valve \201 brosis produc es aortic and mitral regurgitation. Antibiotic therapy appears to be effective, but relapse s are not uncommon. Other bacterial infections occasionally associated with cardiac involvement include legione lla, salmonella, psittacosis, and Streptococcus (see b Acute rheumatic fever, p. 146). Tube rculous myocarditis is rare unless there is pericarditis (see b Tuberculous pericarditis, p . 468). Spirochetal myocarditis \200 About 10 % of patients with Lyme disease (caused by the tick -borne spirochete Borrelia burgdorferi ) have evidence of cardiac involvement \200\224 a combinat ion of direct muscle invasion by the spirochete together with immune-mediated damage. Altho ugh this normally takes the form of AV-conduction abnormalities, LV dysfunction can be pres ent. Syncope due to complete heart block is frequent, and there are often associated ventri cular escape rhythms. VT is uncommon. A positive gallium or indium antimyosin antibody scan may point toward suspected cardiac involvement. Patients with 2nd- or 3rd-degree heart blo ck require hospital admission and monitoring. Treatment is with IV penicillin, and temporar y pacing (if required). The role of steroids and aspirin is unclear. Leptospirosis (Weil disease): cardiac involvement is seen in the more severe presentations. Interstitial myocarditis with involvement of the papillary muscles is seen; conduction def ects, aortitis, and coronary arteritis have been described. Syphillis most commonly produces an aortitis, and direct involvement of the myocardium with gummae is rare (see b Cardiovascular syphilis, p. 662). FUNGAL MYOCARDITIS 455 Protozoal myocarditis \200 In South America, the parasite Trypanosoma cruzi causes the my ocarditis Chagas \200\231 disease, which is a signi \201 cant public health problem (see b Chagas \200\231 disease, p. 660). In the acute phase, it can cause severe myocarditis resulting in CCF and death. Histologically, parasites can be seen lying alongside the myo \201 bres. I mmune lysis by antibody- and cell- mediated immunity directed against T. cruzi antigens ads orbed onto the myocardium appears to be the mechanism of damage. Young children more common ly develop the acute disease and are more severely affected than adults. After an average of 20 years, 730 % of patients develop \201 ndings of chronic Chagas \200\231 disease. Clinical manifestations vary from asymptomatic seropositivity to progress ive cardiac chamber dilatation, with resultant severe CCF. AV conduction defects also occur . Histologically, there is extensive \201 brosis but no parasites are seen. Fatigue, peri pheral oedema, ascites, and hepatomegaly are seen. Ventricular arrhythmias are common: mult ifocal VEs and bouts of VT occur, culminating in syncope and SCD. ECHO shows features of di lated cardiomyopathy; in advanced cases, the appearances are distinctive, with posterior hy pokinesis with relativly preserved septal motion. Diagnosis is with the complement \201 xation test (Machado \200\223Guerreiro), indirect i mmuno \202 uorescence, or enzyme-linked immunosorbent assay (ELISA). Treatment is supporti ve; amiodarone is useful for ventricular arrhythmias; anticoagulation prevents thrombolism. Antiparasitic agents reduce parisitaemia, but there is no evidence that they cure the dise ase. Myocardial involvement with other protozoa (e.g. trypanosomes, toxoplasma, or malaria) is rare and usually asymptomatic. Severe fatal disease is occasiona lly seen. Fungal myocarditis \200 Fungal infection is rare and seen in patients with concomitant malignant disease or those receiving chemotherapy, steroids, or other immunosuppressive the rapy. Other predisposing factors include cardiac surgery, HIV infection, and IV drug use. Organisms implicated include Actinomyces, Aspergillus, Candida, Cryptococcus, and Histoplas ma. Generalized coccidioidomycosis generally causes epicardial lesions with pericarditis, p rogressing on to constrictive pericarditis (see b Constrictive pericarditis, p. 464). Myoca rdial involvement has been described. 456 CHAPTER 8 Heart muscle diseases Toxic and metabolic myocarditis A variety of drugs, chemical agents, and physical agents (e .g. radiation, heat) may result in myocardial damage. Cardiac involvement in systemic disea se is discussed in b Chapter 13, Multisystem disorders, p. 617. Anthracyclines (daunorubici n and adriamycin): These drugs inhibit nucleic acid synthesis and can produce acute and lat e toxicity. Acute cardiotox- icity includes arrhythmias, acute LV dysfunction, a pericardit is-myocarditis syndrome, MI, and SCD. Late cardiotoxicity is due to a dose-dependent degene rative cardiomyopathy that manifests anywhere from weeks to months after the last dose. Sym ptoms can be dif \201 cult to control, and cardiac transplantation has been used in cases where \200\230cancer cure \200\231 has been achieved. Cocaine: This produces chest pain, sweating, and palpitations. In a minority there is myoca rdial ischaemia due to coronary vasoconstriction or throm- botic occlusion of the coronary. Associated \201 ndings include ventricular arrhythmias, and SCD. Treatment is supportive and with B -blockers. Catecholamines: Severe reversible dilated cardiomyopathy has been de scribed with phaeochromocytoma, as well as treatment with high doses of catecholamines and excessive doses of B -agonists in decompensated pulmonary disease. Aspirin and dipyridamole may offer some protection, suggesting a role for platelets in the pathogenesis. Carbon monoxide: Poisoning usually results in central nervous system (CNS) depression, but subendocardial myocardial necrosis is seen. Palpitations, sinus tachycardia, AF, and ventri cular arrhythmias may be seen. ECG abnormalities are common. Treatment with 100 % oxygen, b ed rest, and supportive treatment for arrhythmias is usually effective. Electrolyte abnormalities: Chronic hypocalcaemia is associated with CCF that only responds to restoration of serum calcium. Rapid blood transfu- sion (citrated blood) has been descri bed to result in transient LV dysfunc- tion, due to low serum calcium levels. Severe hypoph osphataemia can also result in reversible LV impairment, restored by correcting the phospha te levels. Hypomagnesaemia is associated with SVT and VT (especially in the context of digi talis toxicity), and focal myocardial necrosis is seen. De \201 ciency of taurine and carnitine: Is associated with a DCM, and in the case of carn itine, supplementation can lead to symptomatic and functional improvement. Myocardial carni tine levels are reduced in patients with DCM but the signi \201 cance of this is still deb ated. Selenium de \201 ciency accounts for a type of DCM seen in parts of rural China, and is occasionally seen in patients on total parenteral nutrition (TPN) without selenium supp lements. TOXIC AND METABOLIC MYOCARDITIS 457 Hypersensitivity myocarditis (eosinophilia and myocardial in \201 ltraton with eosinophils and giant cells) has been described with a variety of drugs, including antibiotics (penici llins, amphotericin, chloramphenicol, tetracycline, sulphonamides), anti-epileptics (phenyt oin, carbamazepine), antituberculous drugs (isoniazid), non-steroidal anti-in \202 ammator y drugs (NSAIDs; indomethacin, phenylbutazone), diuretics (spironolactone, hydrochlorothiaz ide, acetazolamide), sulphonylureas, and amitryptiline. It is rarely recognized clinically. The offending drug should be stopped, and steroids may be required in severe cases. This page intentionally left blank 459 Chapter 9 Pericardial diseases Etiology 460 Syndromes of pericardial disease 461 Acute pericarditis without effusion 461 P ericardial effusion with or without tamponade 462 Constrictive pericarditis 464 Effusive-co nstrictive pericarditis 465 Calci \201 c pericarditis without constriction 465 Viral peric arditis 466 Tuberculous pericarditis 468 Uraemic pericarditis 469 Neoplastic pericardial di sease 470 Myxoedematous effusion 470 Non-tuberculous bacterial (purulent) pericarditis 471 Radiation pericarditis 471 Drugs and toxins 472 Postcardiotomy syndrome 472 Post-infarction pericarditis 472 Rheumatic fever 473 Autoimmune pericarditis 473 Traumatic pericarditis 47 3 Fungal pericarditis 474 Amoebic pericarditis 474 Constrictive pericarditis vs. restrictiv e myocardial disease 475 Pericardial \202 uid analysis 476 460 CHAPTER 9 Pericardial diseases Etiology The pericardium may be involved in the large number of disease processes listed in the box below. In some patients, pericardial disease is the primary disease process domina ting the clinical picture, whereas in others it is a manifestation of a systemic disease. T he most common causes are idio- pathic, viral, uraemic, neoplastic, tuberculous pericarditi s, and acute myo- cardial infarction (MI). The spectrum of pericardial disease is determine d by the age and social circumstances of the patient. In an elderly North American and West ern European population, the commonest causes are malignancy, followed by uraemia and MI. I n less privileged communities and in developing countries, tuberculosis (TB) is still the p redominant cause of pericardial disease. Causes of pericardial disease \200 Infections bacterial: Mycobacterium tuberculosis, Staphylococcus, Pneomococcus, Meningococcus, Mycoplasma viral: Coxsackie, cytomegalovirus (CMV), ECHO, Epstein \200\223Barr virus (EBV), in \202 u enza, human immunode \201 ciency virus (HIV), mumps, Parvo B19, rubella, varicella fungal: histoplasmosis, blastomycosis \200 parasitic: amoebiasis Autoimmune and hypersensitivity diseases collagen vascular diseases: systemic lupus erythematosus, polyarteritis nodosa, scleroderma, dermatomyositis type 2 autoimmune disorders: rheumatic fever, autoreactive pericarditis, post-MI and postpe ricardiotomy syndromes drug-induced: hydralazine, procainamide, penicillin, phenylbutazone other autoimmune disorders: rheumatoid arthritis, ankylosing spondylitis Pericardial involvement by disease in surrounding organs heart: acute MI, myocarditis \200 lung: pulmonary infarction, pneumonia Malignant disease primary: mesothelioma, sarcoma, \201 broma, lipoma \200 secondary: lung carcinoma, brea st carcinoma, melanoma, lymphoma, leukemia \200 Bleeding into the pericardium trauma: penetrating and non-penetrating \200 dissecting aortic aneurysm \200 haemorrhag ic diathesis: leukemia, scurvy \200 anticoagulants: warfarin Metabolic disorders uraemia, dialysis-related, myxoedema, gout Miscellaneous acute idiopathic pericarditis, radiation, sarcoidosis, amyloidosis, familial Mediterranean fever ACUTE PERICARDITIS WITHOUT EFFUSION 461 Syndromes of pericardial disease Pericardial reaction to the various disease processes is l imited, and we are thus able to distinguish \201 ve clinical and pathological forms of pe ricarditis: \200 acute pericarditis without effusion \200 pericardial effusion with or without tamponade \200 constrictive pericarditis \200 effusive-constrictive pericarditi s \200 calci \201 c pericarditis without constriction. Acute pericarditis without effusion ( \200\230Dry \200\231 pericarditis) Etiology: Any of t he causes listed in the box on b Etiology, p. 460 may cause dry pericarditis. The clinical syndrome is commonly seen in acute viral pericarditis or after MI. Pathology: There is a \201 brinous exudate with an in \202 ammatory reaction involving t he visceral and parietal pericardium. The epicardium is also involved and this accounts for the electrocardiography (ECG) changes that are seen, and the rise in cardiac enzymes (e.g. troponin I). Symptoms: Sharp, stabbing, central chest pain is common, with radiation to the shoulders an d upper arm. It is relieved by sitting up and leaning forward, and aggravated by lying down , and may be accentuated by inspiration, cough, swallowing, or movement of the trunk. Fever , night sweats, and other constitutional symptoms may be present, depending on the underlyi ng cause. Signs: A pericardial friction rub is frequently heard. This is a super \201 cial, scratchy , grating sound that is best heard in the second to fourth intercostal spaces when pressure is exerted on the diaphragm of the stethoscope. Positioning the patient leaning forward an d listening in held inspiration may bring it out. The rub is classically described as being triphasic. Usually you hear at least two components due to atrial systole and ventricular systole. Occasionally, a third component attributed to rapid ventricular \201 lling is he ard. ECG: The patient is usually in sinus rhythm but atrial \201 brillation (AF) may occur. In the early stages there is widespread ST segment elevation with concavity directed upwards, and PR segment deviation opposite to the polarity of the P wave. After a few days the ST s egments, followed by PR segments, return to normal, and T waves become inverted. Chest X-ray (CXR): The cardiac shadow is not enlarged in dry pericarditis. Differential diagnosis: Acute pericarditis must be differentiated from MI, spontaneous pneu mothorax, and pleurisy. Diagnosis of acute pericarditis is based on typical symptoms of chest pain, pericardial rub , and/or characteristic ECG changes. Management: Treat the underlying cause. Good pain relief can be achieved by the use of non- steroidal anti-in \202 ammatory agents (NSAIDs). 462 CHAPTER 9 Pericardial diseases Pericardial effusion with or without tamponade Etiology: Any of the causes listed in the bo x on b Etiology, p. 460 may cause pericardial effusion. Large effusions are common with neo plasia, TB, uraemic pericarditis, and myxoedema. Pathology: In addition to \201 brinous in \202 ammation, there is signi \201 cant \202 uid exudation. The pericardial \202 uid may be serous, sero-sanguineous, haemorrhagi c, or purulent, depending on the underlying cause. Haemorrhagic effusion is common in TB or neoplasia. Brownish \202 uid with an anchovy-sauce appearance is highly suggestive of am oebic pericarditis. Clinical features: The clinical presentation varies, depending on the rate of accummulation of the \202 uid, the amount of \202 uid that accumulates, and the stage at which the p atient is \201 rst seen. Symptoms: Chest pain may be typically pericardial (as described under dry pericarditis), or it may be dull and heavy due to distension of the pericardium. Dyspnoea is common, and ort hopnoea may occur later in the course of the disease. Cough may be present due to compressi on of surrounding structures. Constitutional symptoms may be present, depending on the caus e of the disease. Signs: Typically, praecordial dullness extends beyond the apex beat (which may be impalpabl e), and dullness is present to the right of the sternum. Dullness and bronchial breathing a t the left base posteriorly may be found, due to compression of the left lower lobe bronchu s (Ewart \200\231s sign). Cardiac tamponade should be considered in a patient with hypotens ion, raised jugular venous pressure (JVP), and quiet heart sounds (Beck \200\231s triad). T he primary defect in cardiac tamponade is interference with diastolic \201 lling of the h eart. The other clinical features of cardiac tamponade are the presence of tachycardia, pul sus paradoxus (fall in systolic blood pressure on inspiration of > 10 mmHg or inspiratory f all in systolic blood pressure that exceeds half the pulse pressure), elevated JVP with bri sk \200\230x \200\231 descents and absent \200\230y \200\231 descents, rise in JVP on ins piration (Kussmaul \200\231s sign), dyspnoea or tachypnoea with clear lungs, and hepatomega ly. ECG: Sinus tachycardia, generalized low-voltage QRS complexes with non-speci \201 c ST seg ment and T-wave changes. Electrical alternans, involving the QRS complex, suggests the pres ence of a massive pericardial effusion. Total electrical alternans (P-QRS-T), which is unco mmon, is pathognomonic of cardiac tamponade. Echocardiography: Is diagnostic, showing an ECHO-free zone surrounding the heart. The \202 uid may not be evenly distributed. Diastolic collapse of the right ventricle and right atrium indicate cardiac tamponade. The following features are more common in patients with tuberculous or malignant causes of pericardial effusion: soft tissue density masses, thick ening of the visceral pericardium, and presence of \201 brinous strands. The hallmark of benign, idiopathic effusion is a clear ECHO-free space, whereas malignancy, bacterial infec tion, and haemorrhagic effusions are more likely to have solid components or stranding. PERICARDIAL EFFUSION WITH OR WITHOUT TAMPONADE 463 CXR: Shows a large globular heart, usually with clear lung \201 elds. Cardiac catheterization: Establishes the diagnosis and severity of tamponade. The important \201 ndings are: \200 equilibration of mean right atrial, right ventricular end-diasto lic, and mean capillary wedge pressure rapid \200\230x \200\231 descent on the right atrial pressure waveform \200 pulsus parad oxus. Differential diagnosis: Myocardial infarction and pulmonary embolism. Management \200 When an effusion does not cause haemodynamic impairment and the cause is known (e.g. uraemia, myxoedema), then no further investigations are necessary and the treat ment consists of treating the underlying cause. If the cause is not known, then pericardiocentesis must be considered. Aspiration of the \202 uid helps to establish the nature of the effusion (see b Pericardial \202 uid analys is, p. 476). Cardiac tamponade is a life-threatening condition: urgent pericardial aspiration is necessary (see b pp. 814 \200\2236). Surgical drainage is indicated for haemo pericardium or purulent pericarditis. 464 CHAPTER 9 Pericardial diseases Constrictive pericarditis Etiology: Constrictive pericarditis is usually due to TB. Other c auses are mediastinal irradiation, purulent pericarditis, previous trauma (surgical or non- surgical) with infection of the pericardial space, and, very rarely, viral pericarditis. Pathology: The pericardium becomes a dense mass of \201 brous tissue and this may be calc i \201 ed. This results in encasement of the heart within a non-expansile pericardium. Symptoms: Dyspnoea, oedema and abdominal swelling due to ascites and hepatomegaly. Signs: Small volume pulse and pulsus paradoxus. JVP is always elevated, usually very high w ith prominent \200\230x \200\231 and \200\230y \200\231 descents. A diastolic knock is us ually felt at the left sternal border due to the sudden halting of the ventricles during di astolic \201 lling. The apex beat may be impalpable. Heart sounds are usually soft, and a n early third sound coincident with the diastolic knock is usually heard. In the pulmonary area there is sudden instantaneous widened splitting of the second sound that occurs follow ing the \201 rst heartbeat of inspiration (Vogelpoel \200\223Beck sign). The liver is com monly grossly enlarged, ascites is marked, and peripheral oedema is present. ECG: Is abnormal in virtually every case, but changes are non-speci \201 c. (i.e. generali zed low-voltage QRS complexes, and widespread \202 attening and inversion of T waves). AF is common in the chronic form. CXR: A normal or near-normal cardiac size in the presence of marked venous distension or he art failure is suggestive of constrictive pericarditis or restrictive cardiomyopathy. Peric ardial calci \201 cation is diagnostic but its incidence varies from 5 % to 70 % of cases in different series. Echocardiography: Pericardial thickening may be present. There is a restrictive mitral \201 lling pattern on Doppler, with respiratory variation of > 25 % over the AV valves. Computed tomography (CT) and magnetic resonance imaging (MRI) scan: These techniques demons trate pericardial thickening ( > 5 mm). Cardiac catheterization: This demonstrates elevation and equalization of \201 lling press ures. In the typical case, the difference in \201 lling pressures between the right ventr icle and left ventricle does not exceed 6 mmHg. The right atrial waveform shows rapid \200 \230x \200\231 and \200\230y \200\231 descents, and the mean pressure does not decrease no rmally with inspiration, or may show Kussmaul \200\231s sign. Management: Constrictive pericarditis is treated by surgical removal of the \201 brous co nstrictive tissue (pericardiectomy). CALCIFIC PERICARDITIS WITHOUT CONSTRICTION 465 Effusive-constrictive pericarditis Etiology: This is characteristically encountered in active TB pericarditis, where there are signs of both pericardial effusion or tamponade and constriction. It may also occur in neo plastic, radiation, and septic pericarditis. Clinical presentation: Symptoms are usually those of constriction. Examination reveals puls us paradoxus, raised JVP with prominent \200\230x \200\231 and \200\230y \200\231 descent s. The CXR shows an enlarged cardiac silhouette like that of pericardial effusion. Diagnosis: The clue to diagnosis is persistent signs of constriction following adequate per icardial drainage. Management: Treatment of the underlying cause and pericardial drainage is indicated. Perica rdiectomy is indicated should haemodynamics not improve. Calci \201 c pericarditis without constriction This condition is usually discovered during routine radiological examina- tion, which demonstrates pericardial calci \201 cation. The re are no symptoms and signs of constriction, and the cause is usually unknown. 466 CHAPTER 9 Pericardial diseases Viral pericarditis Clinical presentation: Most patients present with a history of upper res piratory tract infection within the preceding three weeks. The viruses most frequently resp onsible include Coxsackie B, ECHO, mumps, in \202 uenza, and varicella. Pericardial pain, fever, and malaise are typical. The physical examination reveals a pericardial friction rub and/or characteristic changes of acute pericarditis on ECG. Course: In the majority of patients, the illness resolves spontaneously in one to two weeks . In some patients, the illness recurs on at least one occasion in the next few weeks or mo nths, and in 20 % of patients there are multiple recurrences in the ensuing months or years (benign relapsing pericarditis). Diagnosis: It is important to search for an underlying disease (see the box on b Etiology, p. 460) that may require speci \201 c therapy. In most cases of suspected viral pericardit is, special studies for aetiologic agents are not necessary because of the low diagnostic y ield of viral studies and lack of speci \201 c therapy for viral disease. Treatment: NSAIDs are effective in most patients with viral pericarditis. There are no data from randomized controlled trials to guide treatment for relapsing patients who do not res pond to NSAIDs. Corticosteroids (prednisone 1 \200\2231.5 mg/kg for at least 1 month) provi de symptomatic relief in most patients; symptoms recur in many patients when the prednisone dose is reduced. Colchicine (2 mg/day for 1 \200\2232 days, followed by 1 mg/ day) may be effective when NSAIDs and corticosteroids fail to prevent relapses. If patients do not resp ond adequately, azathioprine (75 \200\223100 mg/ day) or cyclophosphamide may be added. Per icardiectomy is indicated only in frequent and highly symptomatic recurrences that are resi stant to medical therapy. However, postpericardiectomy recurrences may occur, possibly due to incomplete resection of the pericardium. This page intentionally left blank 468 CHAPTER 9 Pericardial diseases