Ablation of a therapy-resistant posteroseptal accessory atrioventricular pathway: going for gold.

Posteroseptal accessory pathways are sometimes resistant to ablation because of the complex anatomy of this region. Ex-vivo experiments have demonstrated that gold-tip radiofrequency ablation catheters create deeper lesions than conventional platinum-iridium tip catheters. This case of a 62-year-old man with Wolf-Parkinson-White syndrome illustrates that the ability to create such lesions can be a very useful option when previous attempts with platinum-iridium tip catheters have failed.

Functional mitral regurgitation at rest determines the acute hemodynamic response to cardiac resynchronization therapy during exercise: an acute exercise echocardiographic study.

BACKGROUND: Cardiac resynchronization therapy (CRT) acutely enhances forward stroke volume (FSV) during exercise by reducing the severity of functional mitral regurgitation (MR) in patients with systolic chronic heart failure. Whether CRT increases FSV in patients without functional MR at rest is unknown. Accordingly, the aim of the study was to compare the effect of CRT on exercise-induced increase in FSV in patients with chronic heart failure with or without functional MR at rest. METHODS AND RESULTS: Forty-one patients with systolic chronic heart failure who had recently undergone CRT performed 2 exercise stress echocardiography tests, the first with CRT On and the second with CRT Off. Twenty-six patients had more than trivial MR (effective regurgitant orifice [ERO] < 10 mm2 in 16 patients, < 20 mm2 in 8 patients, and > or = 20 mm2 in 2 patients), and 15 patients had no MR at rest. Mean exercise-induced change (Delta) in mitral ERO was reduced by CRT (8 +/- 7 mm2 vs 1 +/- 4 mm2, P < .00001). In patients with functional MR at rest, Delta FSV during dynamic exercise was greater with CRT On than CRT Off (4 +/- 8 vs -2 +/- 7 mL, P = .0002), whereas CRT did not significantly affect Delta FSV in patients without MR at rest (9 +/- 9 mL vs 9 +/- 9 mL, P = .93). Similarly, Delta cardiac output was greater with CRT On than CRT Off (1.6 +/- 1.2 L/min vs 1.1 +/- 1.2 L/min, P = .002) in patients with functional MR at rest, whereas Delta cardiac output was similar with CRT On and CRT Off in patients without MR at rest (1.9 +/- 1.4 L/min vs 2.0 +/- 1.2 L/min, P = .59). Severity of functional MR decreased or failed to increase, whereas cardiac output improved during exercise in 9 of 26 patients (34%) with CRT On and in only 2 of 26 patients (8%) with CRT Off (P = .039). CONCLUSION: Functional MR at rest may be an important determinant of the acute hemodynamic response to CRT during exercise.

Assessment of papillary fibroelastomas with live three-dimensional transthoracic echocardiography.

Seven consecutive patients presenting with typical echocardiographic features of papillary fibroelastoma requiring surgery were studied. All patients underwent standard two-dimensional (2D) transthoracic echocardiography (TTE) followed by live three-dimensional (live 3D) echocardiography with data set storage allowing analysis with systematic cropping of the acquired 3D data and volume measurement of the lesions. Assessment of papillary fibroelastoma by 2D and live 3D TTE was compared to operative findings. The feasibility of live 3D echocardiography in this setting was 100%. The quality of images was considered as optimal in three patients, good in three patients, and poor in one patient. A typical speckled appearance of the tumor was observed in three patients presenting with large tumors. The location of the tumor attachment was precisely defined in all but one patient, with a clear improvement in spatial assessment with live 3D TTE in three patients. Live 3D TTE also improved the operative planning in three patients. Live 3D TTE appears to be useful in the assessment of intracardiac tumors as small as papillary fibroelastomas, leading to a comprehensive approach of the lesion and facilitating the operative planning.

Myocardial asynchronism is a determinant of changes in functional mitral regurgitation severity during dynamic exercise in patients with chronic heart failure due to severe left ventricular systolic dysfunction.

AIMS: Functional mitral regurgitation (MR) and myocardial asynchronism occur commonly in patients with dilated cardiomyopathy and affect adversely their prognosis and symptoms. The aim of this study was to evaluate the mechanisms of changes in MR severity during dynamic exercise in patients with chronic heart failure (CHF). METHODS AND RESULTS: Seventy patients with CHF due to left ventricular (LV) systolic dysfunction [LV ejection fraction (EF) <40%] and functional MR were studied. All were in sinus rhythm. Medications were left unchanged for the study. Each patient performed a maximal symptom-limited exercise test with continuous 2D-Doppler echocardiography. Mitral regurgitant volume (RV) and effective regurgitant orifice (ERO) were determined at rest and during exercise. LV asynchrony using Doppler tissue imaging and interventricular asynchrony using conventional pulsed-Doppler were evaluated at rest. Resting LV EF averaged 25+/-8%. Mean resting LV and interventricular mechanical delays were 56+/-50 and 43+/-37 ms, respectively. The overall median values for mitral ERO and RV did not significantly change during dynamic exercise (11 [7-16] vs. 11 [6-21] mm2 and 14 [10-22] vs. 12 [9-23] mL, respectively). However, changes in mitral ERO and RV were individually variable and significantly correlated with the degree of LV asynchronism (r=0.66, P<0.0001 and r=0.66, P<0.0001, respectively). CONCLUSION: Changes in MR are variable during dynamic exercise. LV asynchronism at rest substantially contributes to worsening of functional MR during dynamic exercise in patients with CHF due to LV systolic dysfunction.