Syed, Faisal F.

Coronary Artery Ventricular Tachycardia. Background The coronary cusps have been well described as a successful site for ablation in patients with symptomatic outflow tract ventricular tachycardia. The earliest site of activation is rarely found at the ostia or into the main coronary arteries. The exact anatomic substrate, diagnostic characteristics, and therapeutic approaches for such instances are poorly understood. Methods We retrospectively reviewed outflow tract ventricular arrhythmia (OTVA) ablations done at Mayo Clinic Rochester from 2003 to 2011 (total VT: 414; outflow tract VT: 106). Three cases were identified where the earliest site of activation was not within the cusp but rather at or within the coronary ostia (3/414 for all VT: 0.7%; 3/106 for all OTVT: 2.8%). Results In 1 patient, the left main coronary artery (LMCA) was found to have electrograms (EGMs) recorded with bipolar mapping that preceded activation in the cusps or the left ventricular outflow tract. In 2 cases, the right coronary ostium and proximal right coronary artery recorded the earliest signals. Intracardiac echocardiographic guidance was used to successfully ablate these arrhythmias targeting the aortic route (1 patient) or the right coronary cusp (2 patients), and essentially isolated the focus of origin from the ventricular outflow tracts. Detailed mapping of surrounding structures, including the atrial appendages, the contralateral outflow tract, and the coronary venous system excluded far‐field mapping in the artery as a cause for early activation at the ostial location. Local EGM characteristics suggested an unusually lengthy supravalvar myocardial extension as the likely arrhythmogenic substrate. Ablation was successful without coronary arterial or valvular injury and without valvular or root stenosis. Conclusions Endocardial ablation isolating foci of origin in the vicinity of the coronary ostia is a challenging procedure but can be performed safely with appropriate visualization and is effective in the treatment of OTVA.

The last decade has witnessed major advances in our understanding of the epidemiology and pathophysiology of HIV-related cardiovascular disease in sub-Saharan Africa. In this review, we summarise these and discuss clinically relevant advances in diagnosis and treatment. In the Heart of Soweto Study, 10% of patients with newly diagnosed cardiovascular disease were HIV positive, and the most common HIV-related presentations were cardiomyopathy (38%), pericardial disease (13%) and pulmonary arterial hypertension (8%). HIV-related cardiomyopathy is more common with increased immunosuppression and HIV viraemia. With adequate antiretroviral therapy, the prevalence is low. Contributing factors such as malnutrition and genetic predisposition are under investigation. In other settings, pericardial disease is the most common presentation of HIV-related cardiovascular disease (over 40%), and over 90% of pericardial effusions are due to Mycobacterium tuberculosis (TB) pericarditis. HIV-associated TB pericarditis is associated with a greater prevalence of myopericarditis, a lower rate of progression to constriction, and markedly increased mortality. The role of steroids is currently under investigation in the form of a randomised controlled trial. HIV-associated pulmonary hypertension is significantly more common in sub-Saharan Africa than in developed countries, possibly as a result of interactions between HIV and other infectious agents, with very limited treatment options. It has recently been recognised that patients with HIV are at increased risk of sudden death. Infection with HIV is independently associated with QT prolongation, which is more marked with hepatitis C co-infection and associated with a 4.5-fold higher than expected rate of sudden death. The contribution of coronary disease to the overall burden of HIV-associated cardiovascular disease is still low in sub-Saharan Africa.