The most common symptoms of COVID-19 are pertinent to lungs. Fever, cough, sputum production, fatigue and shortness of breath were the common symptoms reported based on the studies from China. As COVID-19 cases continue to rise, symptoms of other organs like heart and blood are being reported more often.
American Heart Association published an article on April 7, 2020, describing the effects of COVID-19 on heart. The study reported that 20-30% of the hospitalized COVID-19 patients have heart injury contributing to 40% of deaths, either exclusively or in conjunction with lung failure.
Troponins are considered as the biomarker for heart injury. Troponins are significantly elevated when heart is involved in patients with COVID-19. Elevated Troponins due to heart injury is a major risk factor for death, more significant than age, diabetes, chronic lung disease, or prior history of heart disease. Heart involvement is commonly seen in sick patients admitted to ICU.
The study reported that the mechanisms of heart injury are not well understood. It could be related to direct heart muscle infection by SARS-CoV-2 virus, stress related to lung failure, indirect injury due to extensive inflammation or combination of all the three factors. Autopsies revealed heart tissue damage but there is no data demonstrating the presence of SARS-CoV-2 in the heart tissue.
Damage to the heart tissue may result in congestive heart failure. COVID-19 patients may have signs and symptoms of congestive heart failure, especially in patients admitted to the hospital. Blood pressure abnormalities are also commonly identified in COVID-19 patients. The study reported that abnormal heart rhythms are also commonly seen when COVID-19 patients. Palpitations are seen in 7.3% of patients. Abnormal heart rhythms may occur due to low oxygenation, extensive inflammation or direct heart injury.
Heart attacks can also occur in COVID-19 patients, but it is not clear how often these events occur. There is a strong association between the extent of the lung damage and heart attack. Heart attacks occur more frequently in individuals who already have underlying risk factors like diabetes, high blood pressure, smoking history and obesity.
Akhmerov A et al. COVID-19 and the Heart. Circ Res. 2020 Apr 7. doi: 10.1161/CIRCRESAHA.120.317055.