Reviewing past literature, there is mounting evidence in support of the association between influenza pneumonia and heart diseases and it has been reported that influenza infections have been associated with six-fold increased risk of acute MI [16, 17]. It is likely that COVID-19 also directly and indirectly affects the cardiovascular system and the heart in particular [3]. This topic discuss the prevalence of arrhythmias and conduction system disease in patients with COVID-19.
Triggers of Arrhythmia in Coronavirus Disease 2019 have not yet been specified yet. However, potential reported triggers are as follows [18]. First, electrolyte imbalance caused by COVID-19 symptoms such as diarrhea and complications such as acute kidney injury or severe sepsis are notable causes [19]. Second, SARS-CoV-2-induced myocardial injury due to upregulation of ACE2 receptor during viral invasion and severe hypoxia-induced myocyte necrosis are another potential causes on arrhythmias [20]. Besides, acute myocardial infarction due to demand/supply imbalance and arterial thrombotic event secondary to hypercoagulable state can cause acute arrhythmias [21, 22]. In addition, Stress-induced cardiomyopathy owing to physiological stress and cytokine storm in relation to sepsis and high inflammatory state is another potential mechanism triggering arrhythmias [18]. Moreover, prolonged QTc-inducing malignant ventricular arrhythmias and channelopathies induced by off-label medical therapy and antiviral therapy could be introduced as direct triggers of arrhythmias [23].
The most remarkable result to emerge from the data was the prevalence of advanced AVB in victims of COVID-19. This prevalence was not yet assessd in expired CPVID-19 patients however, the reported range of prevalence of AVB in COVID-19 patients was from 3 to 12 percentages in different articles [13, 14]. All types of AVBs were 40(9.3%) prevalent in our study. Among those with AV block, 12(2.8%) cases suffered from 3rd degree (Complete Heart Block). CHB has been assumed to be a rare ECG feature of COVID-19 and this novel finding was only been reported in a few case studies [5, 7, 9].
Another interesting result was the high prevalence of fragmented QRS, prominent J wave and ST-T wave change. These parameters can be directly related to myocardial injury induced by SARS-CoV-2 infection. In addition, high incidence of S1Q3T3 and LBBB in this study could be an indicator of pulmonary involvement in COVID-19 victims. S1Q3T3 is a relatively specific pattern for pulmonary thromboembolism and a potential cause of death [24].
Moreover, assessing ECG parameters in conduction system disease in victims of COVID-19, ST-T changes, fragmented QRS, axis deviation, presence of S1Q3T3 and poor R wave progression were significantly related to conduction disease in victims of COVID-19. possible suggestive of new onset myocardial infarctions during the infection, increasing the risk of mortality. This may indicate that COVID-19 adversely affects cardiac myocardial tissue more than how it was taken as granted. Besides, our study provides further evidence for the observed ST-T waves changes in COVID-19 patients, suggestive of myocardial infarction or localized myocarditis [25].
Compatible with previous studies, the most prevalent arrhythmia was atrial fibrillation [26]. It is alerting that we witnessed these findings in patients who had no evidence of arrhythmia before their admission. Therefore, we suggest future studies scope on the mechanism of arrhythmogenicity of COVID-19.