Assessment of Right Ventricular-Pulmonary Arterial Coupling in Chronic Pulmonary Regurgitation.

BACKGROUND: We hypothesized that noninvasively measured right ventricular (RV) to pulmonary arterial (RV-PA) coupling would be abnormal in chronic pulmonary regurgitation (PR) even in the setting of normal RV ejection fraction, and that RV-PA coupling indices would have a better correlation with peak oxygen consumption (VO2) compared with RV systolic indices alone. METHODS: This was a retrospective study of 129 adults (repaired tetralogy of Fallot [TOF] n = 84 and valvular pulmonic stenosis [VPS] with previous intervention n = 45) with ≥ moderate native PR and RV ejection fraction > 50%. The 84 TOF patients were propensity matched with 84 patients with normal echocardiogram (control); age 28 ± 7 years and male sex n = 39 (46%). RV-PA coupling was measured according to fractional area change (FAC)/RV systolic pressure (RVSP) and tricuspid annular plane systolic excursion (TAPSE)/RVSP. RESULTS: RV systolic function indices were similar between TOF and control groups (FAC 43 ± 6% vs 41 ± 5% [P = 0.164] and TAPSE 22 ± 5 mm vs 24 ± 6 mm [P = 0.263]). However, RV-PA coupling was lower in the TOF group (FAC/RVSP 1.10 ± 0.29 vs 1.48 ± 0.22 [P < 0.001]; TAPSE/RVSP 0.51 ± 0.15 vs 0.78 ± 0.11 [P < 0.001]) because of higher RV afterload (RVSP 42 ± 3 mm Hg vs 31 ± 3 mm Hg [P = 0.012]). FAC/RVSP (r = 0.61; P < 0.001) and TAPSE/RVSP (r = 0.69; P < 0.001) correlated with peak VO2 especially in the patients with impaired exercise capacity whereas FAC and TAPSE were independent of peak VO2. Similar comparisons between VPS and control groups showed no difference in TAPSE and FAC between groups, but lower FAC/RVSP and TAPSE/RVSP in the VPS group. CONCLUSIONS: There is abnormal RV-PA coupling in chronic PR, and noninvasively measured RV-PA coupling might potentially be prognostic because of its correlation with exercise capacity.

Noninvasive assessment of acute changes in atrial electrophysiology after cardioversion by signal-averaged P-wave electrocardiography.

BACKGROUND: Atrial remodeling secondary to atrial fibrillation (AF) may be important in the arrhythmogenic process. Unfortunately, the study of electrophysiologic remodeling in humans has been limited by the invasive nature of most tests of electrophysiologic characteristics. We sought to determine whether changes in atrial electrophysiology occur acutely (within the first hour) after cardioversion and whether these changes could be detected noninvasively by measuring the signal-averaged P-wave. METHODS: The filtered P-wave duration (FPD) was measured by signal-averaged electrocardiography (ECG) at 20 and 60 minutes after cardioversion in 46 patients with AF, and the difference between the two values was calculated. The root-mean-square voltage of the terminal 40 ms of the signal-averaged P-wave at 20 and 60 minutes and the difference between them were also determined. RESULTS: The FPD at 20 minutes was significantly different from that at 60 minutes (153.0 +/- 19.1 vs 159.7 +/- 24.8 ms; P = 0.02). In a univariate linear regression model, none of the clinical variables studied was significantly associated with the change in FPD. The root-mean-square voltage at 20 minutes was not significantly different from that at 60 minutes (5.8 +/- 3.0 vs 5.5 +/- 2.7; P = 0.14). CONCLUSIONS: We conclude that significant changes in atrial electrophysiology occur within the first hour after cardioversion of AF. These changes can be detected by measuring the FPD.

Critical appraisal of transesophageal echocardiography in cardioversion of atrial fibrillation.

Atrial fibrillation is the most common sustained cardiac arrhythmia and an important health concern in the United States because of the increasing aging population. Cardioversion of atrial fibrillation to sinus rhythm to relieve symptoms and to reduce the incidence of thromboembolism is now common practice. Recently, transesophageal echocardiography (TEE)-facilitated cardioversion emerged as an acceptable therapeutic alternative owing to the assumption that early cardioversion can obviate many of the concerns and disadvantages associated with the conventional approach. We review the current standing of TEE-facilitated early cardioversion vis-à-vis the salient cardioversion issues and its potential future role amid evolving cardioversion paradigms.