XS, a 51-year-old gentleman, came to our attention complaining of several weeks of worsening angina now occurring upon minimal exertion. Hypertension was his only cardiovascular risk factor actively treated with an angiotensin converting enzyme (ACE) inhibitor. No other relevant past medical history was noted. Physical examination was unremarkable highlighting clear heart sounds with no added murmurs and normal lung sounds. His blood pressure was 140/85 mmHg whilst his electrocardiogram (ECG), upon presentation, showed normal sinus rhythm (98 b.p.m.) with widespread ST segment depression consistent with diffuse subendocardial ischaemia (Figure ) and a first troponin sample was below the limit of significance. Given the presentation with progressively worsening angina (unstable angina) and the ECG which suggested a large area of myocardium at jeopardy the patient was loaded with aspirin 300 mg and ticagrelor 180 mg and, following a new anginal episode at rest, a decision was made to undergo urgent invasive coronary angiography. The investigation highlighted a left dominant circulation with a severe mid-left anterior descending narrowing with reduced distal coronaryflow [thrombolysis in myocardial infarction (TIMI) 1] and a severe, large, first obtuse marginal (OM1) stenosis which were both treated with drug-eluting stents implantation with excellent angiographic result, no complications and resolution of ECG anomalies (Figures ). A statin (atorvastatin 40 mg) was started as part of standard ACS therapy on top of dual antiplatelet therapy (DAPT) and ramipril, of interest no beta-blocker or other rate limiting drugs were commenced. The first 24 h a free of complications, no arrhythmic episode was registered by telemetry monitoring, a routine echocardiogram was unremarkable showing normal ejection fraction in the absence of regional wall motion abnormalities or major valvular dysfunctions, and the patient received two standard doses of ticagrelor (8 a.m. and 6 p.m.). On the second night of hospital stay, whilst lying in bed, the patient complained of the sudden feeling of lightheadness and profound sweating and called out for medical assistance. Upon medical review the patient denied any other symptoms, in particular any pain or angina, no ischaemic changes were noted on the ECG whilst telemetry monitoring review highlighted a 16 s long asystolic pause (Figure ). The episode was self-limited with return of sinus rhythm thereafter. Electrolytes were checked and found to be within normal limits. Hence, new medications were investigated looking for a possible explanation to the unexpected asystole given also the patient had no history of syncope. Ticagrelor, due to its brady-arrhythmic effect was suspected to be involved and was therefore halted shifting the patient to prasugrel following the administration of a 60 mg loading dose. A temporary pacing line (TPL) was inserted fearing possible further episodes. However, no new brady-arrhythmic episodes were noted on telemetry monitoring and the unused TPL was removed 24 h later. After 2 further days of monitoring, the patient was discharged home on Day 5 post-PCI in excellent general conditions.
A 76-year-old female without a past history of conduction diseases and confirmed past medical history significant for type 2 diabetes mellitus, hypertension, and coronary artery disease post PCI to right coronary artery (RCA) in 2018, treated with aspirin 100 mg, atorvastatin 20 mg, metoprolol tartrate 50 mg, isosorbide mononitrate 20 mg, and basal-bolus insulin, presented to our hospital emergency department with a 5-day history of shortness of breath that was increasing in severity and associated with central chest pain radiating to throat that started 6 h prior to admission. Her vital signs were as follows: blood pressure = 115/73 mmHg, heart rate = 106 beats per minute, temperature = 36.5 C, and oxygen saturation = 95% on room air. Her first 2 sets of troponin T were 104 ng/L and 135 ng/L (normal <14 ng/L), and her transthoracic echocardiogram showed left ventricular regional wall motion abnormalities with an ejection fraction of 38%. Her initial electrocardiogram (ECG) showed T wave inversion in anterolateral leads (V3–V6 leads) as shown in Figure . Therefore, a diagnosis of non-STEMI was made, and she was planned for in-patient coronary angiography (CAG) and hence started on aspirin 300 mg then 100 mg enteric coated (EC) daily, clopidogrel 300 mg then 75 mg daily, and enoxaparin 1 mg/Kg subcutaneous every 12 h.\nOn the second day of admission, she underwent CAG and was found to have 95% stenosis in proximal left anterior descending (LAD) artery, and a patent drug-eluting stent (DES) in the mid-RCA. A DES (3.0 × 33 mm) was placed in the proximal to mid LAD. After the PCI, she was on aspirin 100 mg EC, clopidogrel 150 mg daily, bisoprolol 5 mg, atorvastatin 40 mg, lisinopril 5 mg, spironolactone 12.5 mg daily, furosemide 40 mg intravenous twice daily, and insulin (basal glargine and bolus aspart). Two days after the PCI, it was decided to start the patient on ticagrelor 180 mg as a loading dose followed by 90 mg twice daily and to stop clopidogrel.\nOne hour after receiving ticagrelor loading dose, the patient started to develop dyspnea followed by an episode of unresponsiveness. The review of the telemetry monitoring strips showed bradycardia followed by a sinus pause of 22 s during the episode of unresponsiveness as shown in Figure . Therefore, she was transferred immediately to our cardiac intensive care unit (CICU) where she underwent transvenous pacemaker insertion, which was kept for 2 days, and ticagrelor was switched back to clopidogrel after 24 h of receiving ticagrelor loading dose, by giving a loading dose of 600 mg followed by 75 mg daily. After the removal of the pacemaker, metoprolol 12.5 mg twice daily was started, and she was observed for 2 days and remained stable without any further episodes of bradycardia or sinus pause with a heart rate ranging from 65–75 beats per minute. After which, she was discharged and then seen in the outpatient clinic within 20 days of discharge and had no complaints.