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.
A 47-year-old female with hypertension and hyperlipidemia was admitted to emergency department due to typical angina lasting 2 days. Her blood pressure was 150/80 mm Hg. On electrocardiogram (ECG), there was a sinus rhythm with heart rate of 67 bpm, along with ST depression of 0.5 mm on inferolateral derivations (). Echocardiography showed hypokinesis of mid-lateral wall with an ejection fraction of 48%. We detected slightly increased cardiac troponin level. Because of ACS (NSTEMI), acetylsalicylic acid (300 mg), ticagrelor (a loading dose of 180 mg and maintenance dose of 90 mg twice a day) and intravenous unfractionated heparin (10,000 IU) were given to the patient and then her coronary angiography was performed, which revealed a total occlusion of the distal ndLCx (). After the lesion was predilated with 2.0 × 15 mm sized balloon catheter, a drug eluting stent of 2.5 × 23 mm was implanted and full patency was achieved (). Thereafter, her symptoms dramatically improved. Since her heart rate was 67 beats/min, beta blocker therapy was not started. Approximately 10 h later, ECG showed first degree AVB without symptom (). Her therapy consisting of ASA, ticagrelor, ramipril and statin was continued unchanged. On the next (second) day, the patient experienced mild dizziness with complet AVB, without hemodynamic impairment (). Ticagrelor was stopped and prasugrel was initiated instead. On the third day, her ECG showed again first degree AVB without symptom (). On the fourth day, she had normal sinus rhythm without AVB and symptom (). On the fifth day, the patient was salubriously discharged from the hospital with therapy of ASA, prasugrel, rosuvastatin and ramipril. We did not observe any heart block and/or bradyarrhythmia during the 3 months of follow-up.