A 64-year-old male with a medical history of hypertension, diabetes mellitus and hyperlipidemia and a chronic smoker presented with complaints of chest pain which was sharp, continuous in nature and was aggravated by slight walking or lifting of heavy loads. The patient also had complaints of shortness of breath of Grade 4 according to the Medical Research Council (MRC) Dyspnoea Scale []. He had a body mass index (BMI) of 25.8 Kg/m2. The baseline HbA1c% value was 10.8 gm%. He underwent coronary angiography at the discretion of the concerned cardiologist. A diagnosis of Acute Coronary Syndrome (ACS) with Non-ST elevation Myocardial Infarction (NSTEMI) with an occlusion of 99% in the left circumflex artery (LCX) was made. Percutaneous Coronary Angioplasty (PTCA) was performed on the same day with the placement of one everolimus eluting coronary stent in the LCX.\nA loading dose of 180 mg of ticagrelor was given to the patient just before the PTCA was performed. A thrombolysis in myocardial infarction (TIMI) 3 flow was achieved post the procedure. Blood flow distal to the stent was achieved and the procedure was concluded successfully. The post procedural ejection fraction (EF) was 45%. Post procedural electrocardiogram (ECG) was also performed and it showed a QTc of 402 ms with atrial fibrillation and poor progression of the R wave in leads V4 and V5 (). He got discharged after 2 days with an advice of 180 mg ticagrelor, 75 mg aspirin, 20 mg atorvastatin, 25 mg metoprolol, 25 mg spironolactone, 10 mg furosemide and 1000 mg of metformin daily. He was advised to visit the out-patient department (OPD) of Cardiology after 2 months or the ED in case of any emergency.\nThe patient came to the OPD after 1.5 months with complaints of severe shortness of breath (MRC Dyspnoea Scale Grade 5) along with infrequent bouts of coughs. Vitals were measured and the blood pressure was 104/60 mm Hg, with the pulse being 68/min. On auscultation, no bronchopulmonary abnormality could be inferred. Bilateral clear breath sounds were obtained. A BMI of 24.6 Kg/m2 was recorded. In view of ticagrelor induced dyspnea, ticagrelor was discontinued and 75 mg clopidogrel once daily was started while rest of the medications were kept unchanged. An ECG was obtained and it showed a QTc of 468 ms (16.4% increase) with biphasic T wave in Lead III (). He was advised to visit the Cardiology OPD after 1 month or the ED in case of any emergency.\nThe patient came back after one month for follow-up. He had no complaints of shortness of breath or cough this time. Vitals were measured and blood pressure was 114/78 mm Hg with a pulse rate of 66/min. HbA1c% came out to be 9.6 gm%. An ECG was done and it showed a drastic reduction of the QTc to 425 ms (9.2% reduction) () with slight ST elevation in leads V4 and V5. An echocardiography was also performed and the EF came out to be 50%.
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.