The COVID-19 pandemic, which has affected hundreds of thousands of patients, is an internationally serious threat to health. Due to the urgency of the problem, the article presents a case of acute coronary syndrome (ACS) development with rupture of left ventricular wall and hemorrhagic cardiac tamponade after SARS-CoV-2 infection in 58 years old patient, who was hospitalized for several hours at the Republican Cardiology Center of the Ministry of Healthcare of Chuvash Republic with a severe novel coronavirus infection (COVID-19) diagnosis, SARS-CoV-2 was identified. Concurrent disease was ACS. The patient was admitted to the hospital in a severe condition accompanied by an ambulance team. She complained of breath shortness, pain under left scapula and fast heart rate. Electrocardiogram reported a sinus tachycardia with a heart rate up to 120 b/min, upsloping ST segment elevation up to 1 mm in V1-V6 leads. Computed tomography revealed bilateral viral interstitial pneumonia with 73% affected area. COVID-19 diagnosis was made according to the nasopharyngeal smear by polymerase chain reaction method. There were arterial hypertension and postinfarction cardiosclerosis in medical history (2018 yr.). The state assessment by NEWS2 scale was 11 scores. SaO₂ was 65%. Troponin I level was 0.08 (0.02) ng/ml. Fatal outcome suddenly occurred. There were the signs of viral pneumonia in lungs and perforated defect sized 1.5 cm with irregular edges in cardiac apex in the region of postinfarction cardiosclerosis in dissection. There were interstitial edema, muscle fibers without cross-striation and with signs of intracellular edema in microscopic examination. Thus, ACS with rupture of left ventricular wall and hemorrhagic cardiac tamponade developed in patient in the background of viral pneumonia, that led to fatal outcome.