Anatomical considerations and clinical interpretation of the 12-lead ECG in the prone position: a prospective multicentre study

AIMS

The aim of this study is to provide guidance for the clinical interpretation of electrocardiograms (ECGs) in prone position and to establish the electroanatomic explanations for the possible differences to supine position ECGs that may be observed. Additionally, to determine if prone back ECG can be used as an alternative to standard ECG in patients who may benefit from prone position.

METHODS AND RESULTS

The ECG in supine (standard ECG), prone back (precordial leads placed on the patient's back), and prone anterior position (precordial leads placed in the standard position with the subjects in prone position) were prospectively examined on 85 subjects. Comparisons of ECG parameters between these positions were performed. Computed tomography (CT) scans were performed in both positions to determine possible electroanatomic aetiologies for prone-associated ECG changes. There were significant differences in QRS amplitude in Leads V1-V5 between supine and prone positions. Q waves were more frequently observed in prone back position vs. supine position (V1: 74.1 vs. 10.6%, P < 0.0001; V2: 23.5 vs. 0%, P < 0.0001, respectively). Flat and inverted T waves were more common in prone back leads (V1: 98 vs. 66%, P < 0.0001; V2: 96 vs. 8%, P < 0.0001; V3: 45 vs. 7%, P < 0.0001). The 3D-CT reconstructions measurements corroborated the significant inverse correlation between QRS amplitude and the distance from the centre of the heart to the estimated lead positions.

CONCLUSION

In prone back position ECG, low QRS amplitude should not be misinterpreted as low voltage conditions, neither should Q waves and abnormal T waves are considered anteroseptal myocardial infarction. These changes can be explained by an increased impedance (due to interposing lung tissue) and by the increased distance between the electrodes to the centre of the heart.

Electrocardiographic Features of Patients with COVID-19: An Updated Review

Numerous systemic manifestations, including cardiac involvement in the form of myocardial infarction, myocarditis, and electrocardiographic changes, have been associated with COVID-19..In this review, the authors describe the electrocardiographic features that have been reported to date in patients affected by this disease and their possible underlying mechanisms.

Hypoxic hepatitis in an extensive aortic disecction: case report

Hypoxic hepatitis is an uncommon cause of hepatic damage characterized by a centrolobular necrosis. Its pathophysiology remains unclear. Aortic dissection is a rare but frequently catastrophic event. It is caused by an aortic intimal tear with propagation of a false channel in the media. Depending on the site and extension, it can cause hypoperfusion of any organ leading to cellular ischemia and necrosis. We are presenting a case of hypoxic hepatitis in a patient with an extensive aortic dissection who present to the emergency department.

Insidious onset of intermittent claudication as the primary manifestation of infective endocarditis

Musculoskeletal manifestations of infective endocarditis are well-described in the literature. However, insidious onset of localized calf pain is an uncommon presentation of embolization and may represent a diagnostic challenge owing to the nonspecific nature of the symptoms. This study reviewed the literature and reports a case of infective endocarditis in a patient who presented with bilateral calf pain as the primary complaint and reason for seeking medical attention.