Yves Provost

Adverse Left Ventricular Mechanics in Adults With Repaired Tetralogy of Fallot

Left ventricular (LV) dysfunction is a predictor of adverse outcomes in patients with repaired tetralogy of Fallot (TOF). However, the mechanisms for LV dysfunction are not well understood. The aim of the study was to determine whether the prolonged QRS duration of right branch bundle block was associated with adverse LV mechanics. Seventy-five patients (mean age 31 +/- 2 years) with repaired TOF were studied. LV and right ventricular (RV) volumes and ejection fractions (EFs) were assessed using cardiac magnetic resonance imaging. Vector velocity imaging was used to assess longitudinal strain and intraventricular dyssynchrony. Prolonged QRS duration was associated with increased RV and LV dimensions (p = 0.01) and decreased function (RVEF r = -0.60, p <0.001 and LVEF r = -0.77, p <0.001). In addition, prolonged QRS duration was associated with heterogeneous ventricular mechanical activation and reduced strain in the lateral and septal left ventricle walls. Degree of intraventricular dyssynchrony correlated with LVEF (r = -0.59, p <0.001), QRS duration (r = 0.74, p <0.001), and septal strain (r = 0.70, p <0.001). In conclusion, LV dysfunction and dyssynchrony were observed in patients with TOF and were associated with QRS duration. It was possible that abnormal LV mechanics in combination with RV dysfunction may explain the relation between QRS duration and adverse cardiac outcomes.

Refining the assessment of pulmonary regurgitation in adults after tetralogy of Fallot repair: should we be measuring regurgitant fraction or regurgitant volume?

AIMS Pulmonary regurgitation (PR) is an important determinant of outcome after tetralogy of Fallot (TOF) repair. The physiologic impact of PR on the right ventricle remains incompletely understood. We hypothesized that a volumetric expression of PR would be a better measure of ventricular preload and a more accurate reflection of degree of insufficiency. METHODS AND RESULTS Patients (n = 64) with magnetic resonance imaging after TOF repair were identified. PR was quantified using: (i) phase contrast (PC) analysis of main pulmonary artery flow and (ii) differential right and left ventricular stroke volumes. PR was expressed as a volume (PR(volume)) and percentage of total forward flow (PR(fraction)). The median PC(PR volume) was 19 mL/m(2) (range 0-63 mL/m(2)) and PC(PR fraction) was 29% (range 0-58%). PR(fraction) was found to be highly variable in terms of absolute PR(volume). In those with significant PR, PR(volume) was better than PR(fraction) for the identification of severe RV dilation (receiver-operator curve area: 0.83 vs. 0.71, P = 0.003). PR(volume) using PC analysis was better at differentiating moderate from severe RV dilation (P = 0.005) as compared with PR(fraction) (P = 0.064). CONCLUSION PR(volume) and PR(fraction) are not interchangeable. PR(volume) may be a more accurate reflection of RV preload and may better represent physiologically significant PR as compared with PR(fraction).

Effect of angiotensin receptor blockade on systemic right ventricular function and size: A small, randomized, placebo-controlled study

INTRODUCTION The effects of angiotensin converting enzyme inhibitor on systemic right ventricular size and function are unknown. METHODS Prospective, double blind, randomized, placebo-controlled clinical trial of 1-year therapy with Ramipril in adult patients with DTGA status postatrial baffle procedure. Primary endpoints were change in systemic right ventricular ejection fraction (RVEF) and right ventricular size assessed by magnetic resonance imaging (MRI). RESULTS Seventeen patients were enrolled into the study. Mean age at study enrollment was 26.4+/-5.2 years. Mean baseline RVEF was 44+/-6.5%, mean RVEDV was 206.3+/-75.5 ml. Eight patients were randomized to the treatment group and 9 patients were randomized to the placebo group. RVEF did not improve in the Ramipril group from baseline to 1 year (43.8+/-7.1% vs. 40.9+/-13.3%, p=0.52) and remain unchanged in the placebo group (44.3+/-6.3 vs. 46.3+/-9.6%, p=0.42). RVEDV (184.5+/-56.4 ml vs. 179.6+/-66.4 ml, p=0.64) and RVESV (109.5+/-19.4 ml vs. 111.8+/-30.1, p=0.74) remained unchanged in the Ramipril group from baseline to 1 year as well as in the placebo group (228.1+/-89.2 ml vs. 204.5+/-50.4 ml, p=0.42 and 117.5+/-36.9 ml vs. 117.4+/-26.2 ml, p=0.99, respectively). CONCLUSION One-year treatment with Ramipril does not seem to affect right ventricular function or size in adult patients with systemic right ventricles after a Mustard or Senning procedure. CONDENSED ABSTRACT 17 Adult patients (mean age of 26.4 +/- 5.2 years) with systemic right ventricles were blindly randomized to 1-year treatment with Ramipril placebo. Systemic right ventricular function (RVEF) and size (RVEDV) were assessed by magnetic resonance imaging at baseline and 1 year. RVEF failed to improve in the Ramipril group (43.8+/-7.1% vs. 40.9+/-13.3%, p=0.52) and remain unchanged in the placebo group (44.3+/-6.3 vs. 46.3+/-9.6%, p=0.42). RVEDV remained unchanged in the study group (184.5+/-56.4 ml vs. 179.6+/-66.4 ml, p=0.64 as well as in the placebo group (228.1 +/- 89.2 ml vs. 204.5 +/- 50.4 ml, p = 0.42). One-year treatment with Ramipril does not improve right ventricular function or attenuate remodeling in adult patients with systemic right ventricles.

CT and MR imaging findings in patients with acquired heart disease at risk for sudden cardiac death.

Noninvasive imaging is an important screening and diagnostic tool in conditions associated with sudden cardiac death. The most common cause of sudden cardiac death is coronary artery disease, with myocarditis, cardiac sarcoidosis, and dilated and infiltrative cardiomyopathies being less common acquired causes. Common risk factors for sudden cardiac death, regardless of the disease process, include severe ventricular dysfunction and the presence of macroscopic scar seen at delayed contrast material-enhanced imaging. Recent advances in electrocardiographically (ECG) gated cardiac magnetic resonance (MR) imaging and multidetector computed tomography (CT) have led to increased referrals for cross-sectional imaging; thus, cardiac radiologists should be familiar with the disease entities associated with sudden cardiac death. Inflammatory processes and cardiomyopathies are best depicted with cardiac MR imaging. Steady-state free precession cine sequences coupled with inversion-recovery prepared gradient-echo T1-weighted sequences performed after the intravenous administration of gadolinium-based contrast material should form the basis of cardiac MR imaging protocols for cardiomyopathy. A clinical history that is suggestive of myocardial ischemia, specific requests to exclude coronary artery disease, or contraindications for MR imaging may imply that multidetector CT would be more appropriate. Nevertheless, both cardiac MR imaging and ECG-gated multidetector CT offer robust diagnosis and risk stratification for individual disease processes associated with sudden cardiac death.

Ventricular reconstruction for ischemic cardiomyopathy.

Left ventricular surgical reconstruction has been advocated for patients with coronary artery disease, prior myocardial infarction, and poor left ventricular function. The objective of the approach is to resect or exclude all akinetic or dyskinetic nonfunctioning portions of the ventricular cavity and to restore the left ventricle size and shape toward normal as much as possible. We review the pathophysiology of ischemic cardiomyopathy and suggest guidelines for preoperative assessment and patient selection for ventricular reconstruction. Because of the prevalence and prognostic significance of ventricular arrhythmias in this patient population we include in our operative approach a visually directed ablation procedure in those with significant septal scarring. We describe our operative technique and review results achieved with this approach. The procedure results in a significant decrease in ventricular volume, increase in ejection fraction and improvement in apical geometry. We conclude that in selected patients with ischemic cardiomyopathy, left ventricular reconstruction can be accomplished with low operative mortality and results in significant improvement in left ventricular function. During follow up symptom class is decreased in most patients and overall survival at 5 years is 84% and freedom from sudden death is 96%. Ventricular reconstruction should be considered in all patients with coronary artery disease and akinetic or dyskinetic scar.

Stenosis of the superior limb of the systemic venous baffle following a Mustard procedure: An under-recognized problem

BACKGROUND Patients with atrioventricular concordance and ventriculoarterial discordance (DTGA) and a Mustard procedure may develop stenosis of the superior limb of the systemic venous baffle (SLSVB). The frequency of this complication in an adult cohort was evaluated. METHODS Patients >18 years with DTGA and a Mustard procedure with and without a pacemaker (PM)/implantable cardioverter defibrillator (ICD) were identified through an institutional database. Subjects were included following a cardiac imaging study (computed tomography, magnetic resonance imaging, venography or cardiac catheterization) and follow-up in the PM/ICD or congenital cardiac clinics from 2001 to 2007. The primary end-point was narrowing of the SLSVB (<10mm) on cardiac imaging. Hemodynamically significant narrowing was defined by: azygous vein dilatation with retrograde flow or superior vena cava syndrome or the need for dilatation ± stenting of the SLSVB. RESULTS Narrowing of the SLSVB was observed in 49/112 patients (70 males) age 31 ± 6 years (range 18-49) and was hemodynamically significant in 15/49. Of 29 patients with a PM (23) or ICD (6) and cardiac imaging, 17 had narrowing of the SLSVB which was hemodynamically significant in 8. Non-echocardiographic imaging had a sensitivity of 88% at detecting narrowing of the SLSVB in contrast to pulse-wave Doppler, which yielded a sensitivity of 16% (61% negative predictive value, 88% positive predictive value). CONCLUSIONS In our adult cohort of Mustard patients, narrowing of the SLSVB had a prevalence of 44% and was more likely to be detected by non-echocardiographic imaging. Baffle patency should be evaluated before transvenous device implantation.

Contained Rupture of the Aortic Annulus After Transcatheter Aortic Valve Implantation: Uncommon Presentation of a Rare Complication

We report the case of a contained rupture of the aortic annulus after transcatheter aortic valve implantation. The landing zone tear extended cranially to the aortic root and caudally into the perimembranous septum, creating a restrictive ventricular septal defect and severe paravalvular regurgitation into both ventricles, but no pericardial effusion or hemodynamic collapse. We elected conservative management, which proved to be a reasonable option.

Giant right coronary artery aneurysm on 64-MDCT.

An 81-year-old woman was referred for cardiac computed tomography-angiography (CCTA) after an extracardiac mass was found on echocardiography. CCTA found a giant atherosclerotic right coronary artery aneurysm with a maximal diameter of 80 mm, which was compressing the right atrium and right appendage, proximal superior vena cava, right ventricle inlet and tricuspid annulus.

Coronary artery bypass graft imaging with 256-slice MDCT: surgical concepts, current techniques, and interpretation.

Multidetector computed tomography (MDCT) scanners with current equipment allow for a rapid and robust noninvasive assessment of coronary artery bypass graft (CABG) anatomy and patency. With both appropriate expertise in MDCT techniques and knowledge in CABG imaging interpretation, radiologists should play an important and active role in the postoperative care of patients with bypass grafts. In this pictorial essay, we review the MDCT techniques and anatomy relevant to CABG imaging, interpretation pitfalls, some basic and advanced surgical designs, as well as postoperative graft complications in patients with CABG, with clinical illustrations from our local experience.

Cardiac Magnetic Resonance Imaging and Multidetector Computed Tomography Scan Illustrating Damus–Kaye–Stansel Operation

The Damus–Kaye–Stansel (DKS) operation was first described in 1975 independently by 3 authors, Damus,1 Kaye,2 and Stansel,3 and was soon felt to be an effective method to relieve systemic ventricular outflow–tract obstruction in patients with ventriculoarterial discordance. Since then, the procedure has been applied to patients with several forms of complex congenital heart disease in which systemic outflow is obstructed. The operation consists of an anastomosis of the proximal end of the transected pulmonary artery to the side of the ascending aorta, ensuring unobstructed outflow to the systemic circulation through the pulmonary valve. The pulmonary circulation can be then reestablished by a right ventricle to the distal main pulmonary artery conduit in cases of biventricular repair, or by a Fontan procedure (systemic venous return to the pulmonary artery without the subpulmonary ventricle) in cases in which only a univentricular repair can be offered. We present 2 cases that illustrate the utility of cardiac magnetic resonance imaging and multidetector computed …