Enhanced Response to Drug-Induced QT Interval Lengthening in Patients with Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Patients with heart failure (HF) with reduced ejection fraction demonstrate enhanced response to drug-induced QT interval lengthening and are at increased risk for torsades de pointes. The influence of HF with preserved ejection fraction (HFpEF) on response to drug-induced QT lengthening is unknown. METHODS AND RESULTS: We administered intravenous ibutilide 0.003 mg/kg to 10 patients with HFpEF and 10 age- and sex-matched control subjects without HF. Serial 12-lead electrocardiograms were obtained for determination of QT intervals. Demographics, maximum serum ibutilide concentrations, area under the serum ibutilide concentration vs time curves, and baseline Fridericia-corrected QT (QTF) (417 ± 14 vs 413 ± 15 ms, P = .54) were similar in the HFpEF and control groups. Area under the effect (QTFvs time) curve (AUEC) from 0 to 1.17 hours during and following the ibutilide infusion was greater in the HFpEF group (519 ± 19 vs 497 ± 18 ms·h, P= .04), as was AUEC from 0 to 8.17 hours (3576 ± 125 vs 3428 ± 161 ms·h, P = .03) indicating greater QTF interval exposure. Maximum QTF (454 ± 15 vs 443 ± 22 ms, P = .18) and maximum percent increase in QTF from baseline (8.2 ± 2.1 vs 6.7 ± 1.9%, P = .10) in the 2 groups were not significantly different. CONCLUSIONS: HFpEF is associated with enhanced response to drug-induced QT interval lengthening.

Case Report: Constrictive Pericarditis in a Patient With Isolated Anomalous Right Upper Pulmonary Venous Return.

Thirty-eight-year-old male presented for evaluation of abdominal swelling, lower extremity edema and dyspnea on exertion. Extensive work-up in search of the culprit etiology revealed the presence of an Anomalous Right Upper Pulmonary Venous Return (ARUPVR) into the Superior Vena Cava (SVC). During the attempted repair, the pericardium was found to be thickened and constrictive. Only one other case of co-existent partial anomalous pulmonary venous return and constrictive pericarditis (CP) has been reported. The patient underwent a warden procedure with pericardial stripping with good outcomes at 45 days post-operatively. Thus, the presence of severe heart failure symptoms in the setting of ARUPVR should prompt further investigations. Also, further cases are needed to help guide management in these patients.