Polymorphic ventricular arrhythmia triggered by temporary epicardial right ventricular stimulation after cardiac surgery

Temporary epicardial pacing is commonly used for rhythmic support in the acute postoperative period after cardiac surgery. Clinical studies suggest that pacing in the left ventricular epicardium during resynchronization therapy may be proarrhythmic in a minority of patients. The epicardial pacing increases transmural heterogeneity of repolarization. This could prolong the QT and JT intervals on the electrocardiogram (ECG), with subsequent proarrhythmic effects. The following case describes polymorphic ventricular arrhythmias after temporary epicardial ventricular stimulation

Arrhythmias in Dilated Cardiomyopathy: Diagnosis and Treatment

In patients with dilated cardiomyopathy (DCM), it is possible to find a broad range of bradyrhythmias and tachyarrhythmias. Bradyrhythmias and supraventricular arrhythmias can frequently occur in some familial forms such as lamin A/C mutations. Nonsustained ventricular arrhythmias (VA) are observed in about 40% of patients with DCM, but their prognostic role is not clear, and conflicting data have been published in the last 30 years. Multiple mechanisms can explain atrial and ventricular tachyarrhythmias in DCM. Reentry is associated with slow conduction across surviving muscle bundles within regions of interstitial fibrosis, but other mechanisms can be involved, as nonuniform anisotropy of impulse propagation, ion channel dysfunction, and reduced gap junction function