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.
In May of 2016, a 55-year-old male with history of hypertension, hyperlipidemia, and coronary artery disease (CAD) status after angioplasty of left anterior descending (LAD) artery 2 years ago presented to the emergency room (ER) with substernal chest pain. His cardiac enzymes were not elevated and electrocardiogram (EKG) showed normal sinus rhythm at a rate of 62 bpm with borderline AV conduction delay and right bundle branch block (RBBB) pattern (). The patient was only taking aspirin and had discontinued his statin due to muscle ache and metoprolol because of fatigue. His chest pain was relieved with sublingual nitroglycerin in the ER. In view of his significant history of CAD and typical anginal symptoms, patient underwent cardiac catheterization. It revealed 90 percent stenosis of the left mid circumflex coronary artery which was successfully stented with a drug-eluting stent. Right coronary artery (RCA) showed 50–60% stenosis while LAD showed patent stent. The patient recovered very well. After calculating the GRACE score, the patient was discharged on aspirin and ticagrelor as per the ACC guidelines. He was also prescribed rosuvastatin and metoprolol. Two months after PCI, the patient presented to his primary cardiologist due to worsening fatigue and intermittent dizziness. His metoprolol was stopped. In November, 2016, he was brought by emergency squad to the hospital due to worsening dizziness and diaphoresis at rest. He denied any h/o chest pain, palpitations, nausea, or loss of consciousness. The patient had stopped ticagrelor 1 day prior to this admission since he ran out of it. The patient requested a second opinion on this admission. On physical examination, his blood pressure was 126/66 mmHg and heart rate was regular at 42 beats per minute. The neck was supple with no carotid bruits and cardiac auscultation revealed 2/6 ejection systolic murmur in the left sternal border. Patient's EKG revealed second-degree type II atrioventricular (AV) block which was new (). His cardiac enzymes, thyroid stimulating hormone, serum potassium, and magnesium were within normal range. The patient did not receive ticagrelor further during the admission. Cardiac catheterization revealed RCA stenosis of 60–70% but no intervention was required as this was not the cause of the new onset heart block. We considered starting patient on oral theophylline on admission had the heart block not resolved within 24 hours. His second-degree heart block resolved 2 days after discontinuation of ticagrelor and his EKG showed sinus bradycardia (heart rate = 54 bpm) with borderline AV conduction delay with RBBB pattern () which was similar to his baseline EKG. Clopidogrel was started as an alternative P2Y12 platelet receptor inhibitor and aspirin was continued. He was discharged after an event monitor was placed.