Outcomes of untreated frequent premature ventricular complexes with normal left ventricular function.

OBJECTIVE: The natural history of frequent premature ventricular complexes (PVCs) in association with preserved left ventricular ejection fraction (LVEF) is uncertain. The optimal management of this population is thus undefined. We studied the outcomes of untreated patients with frequent PVCs and preserved LVEF. METHODS: This cohort study prospectively evaluated consecutive patients from 2012 to 2017, with asymptomatic or minimally symptomatic frequent idiopathic PVCs (≥5% PVCs in 24 hours; normal LVEF; no cause identified on comprehensive evaluation). No suppressive therapy (ablation or antiarrhythmic drugs) were used and patients were followed with serial ambulatory ECG monitoring and echocardiography. The primary arrhythmic outcome was reduction in PVC burden to <1% on serial ambulatory monitoring. The primary echocardiographic outcome was a reduction of LVEF to <50%. RESULTS: One hundred patients met inclusion criteria (mean age 51.8 years, 57% female) with a median PVC burden of 18.4%. Reduction to <1% PVCs occurred in 44 of 100 patients (44.0%) at a median of 15.4 months (range 2.6 to 64.3). Recurrence was uncommon (4/44, 9.1%). Four patients (4.3%) with a persistently elevated PVC burden developed left ventricular dysfunction (LVEF <50%) during the follow-up period at a range of 53-71 months. The initial PVC burden did not predict subsequent resolution (HR 1.00(0.97, 1.03); p=0.86). CONCLUSIONS: A strategy of active surveillance is appropriate for the majority of patients with frequent idiopathic PVCs in association with preserved LVEF, owing to the low risk of developing left ventricular systolic dysfunction and the high rate of spontaneous resolution.

Evaluation of syncope: focus on diagnosis and treatment of neurally mediated syncope.

Syncope, defined as a transient loss of consciousness secondary to global cerebral hypoperfusion, is common in the general population. The single most helpful "test" in the evaluation of patients with syncope is a thoughtful history, with recent evidence that structured histories are remarkably effective in arriving at a diagnosis. In addition to the history, physical examination, and electrocardiogram, arriving at a diagnosis of syncope can involve monitoring and provocative strategies. The majority of patients with syncope have neurally mediated syncope and a favourable prognosis. The management of neurally mediated syncope continues to largely revolve around education, avoidance of triggers, reassurance, and counter-pressure maneuvers. The evidence surrounding medical therapy in vasovagal syncope is not strong to date. Pacemaker therapy is reasonable in older patients with recurrent, unpredictable syncope with pauses, but should be considered as a last resort in younger patients.

Premature ventricular contraction-induced cardiomyopathy.

PURPOSE OF REVIEW: There has been a resurgent interest in frequent premature ventricular contractions (PVCs) led by the novel concept that they may be a potential cause of, or at least contribute to, cardiomyopathy. This review evaluates recent advances in our understanding of PVC-induced cardiomyopathy. RECENT FINDINGS: Recent studies have focused on identifying the predictors of PVC-induced cardiomyopathy, with the most consistent predictors being PVC burden and PVC QRS duration. Multiple studies have investigated the effect of catheter ablation on PVC burden and resultant left ventricular function, with the efficacy of catheter ablation and the overall PVC response rates varying between 60 and 88%. After successful ablation, the rates of improvement in left ventricular ejection fraction have varied between 47 and 100%. A recent study raises the question that perhaps even a lower PVC burden could result in PVC cardiomyopathy and adverse outcomes. SUMMARY: There is an increasing body of literature supporting a causal role of frequent PVCs in the development of left ventricular dysfunction. Effective therapy for PVCs exists; however, the optimal indications for therapy have yet to be determined.

Integrating anatomical and functional imaging for the assessment of coronary artery disease.

Coronary artery disease (CAD) is a leading cause of morbidity and mortality. Invasive cardiac angiography with fractional flow reserve measurement allows for the anatomical and functional assessment of CAD. Given the invasive nature of invasive cardiac angiography and the risks of procedure-related complications, research has focused upon noninvasive methods for anatomical and functional measures of CAD. As such, there is growing interest in the development of hybrid imaging because it may provide incremental diagnostic information over each imaging modality alone. We will provide an overview of the evidence to date on the anatomical and functional stratification of CAD and current hybrid techniques.

Right and left ventricular uptake with Rb-82 PET myocardial perfusion imaging: markers of left main or 3 vessel disease.

BACKGROUND: Relative myocardial perfusion imaging may underestimate severity of coronary disease (CAD), particularly in cases of balanced ischemia. Can quantification of peak left (LV) and right (RV) ventricular Rb-82 uptake measurements identify patients with left main or 3 vessel disease? METHODS: Patients (N = 169) who underwent Rb-82 PET MPI and coronary angiography were categorized as having no significant coronary stenosis (n = 60), 1 or 2 vessel disease (n = 81), or left main disease/3 vessel disease (n = 28), based on angiography. Maximal LV and RV ventricular myocardial Rb-82 uptake was measured during stress and rest. RESULTS: Failure to augment LV uptake by >or= 8500 Bq/cc at stress, predicted left main or 3 vessel disease with a sensitivity of 93% and specificity of 61% (area under curve = 0.83). A >or=10% increase in RV: LV uptake ratios with stress over rest was 93% specific (area under curve = 0.74) for left main or 3 vessel disease. These indices incrementally predicted left main or 3 vessel disease compared to models including age, gender, cardiac risk factors, and summed stress and difference scores. CONCLUSION: Quantifying maximal rest and stress LV and RV uptake with PET myocardial perfusion imaging may independently and incrementally identify patients with left main or 3 vessel disease.