Biomedical subjects

Cara A Garofalo

Publications and source records attributed to Cara A Garofalo.

3 recordsLinked to original sources

PubMed2006

Ventricular diastolic stiffness predicts perioperative morbidity and duration of pleural effusions after the Fontan operation.

BACKGROUND: We validated the clinical relevance of ventricular stiffness by examining surgical morbidity in children with univentricular hearts undergoing Fontan operation. We hypothesized that ventricular stiffness affects Fontan morbidity, particularly duration of pleural effusions. METHODS AND RESULTS: Sixteen children with right ventricular (RV) (n =11) or left ventricular (LV) (n =5) dominance were studied intraoperatively at a median age of 3.3 years (1.8 to 5.1). Transesophageal long-axis echocardiograms and ventricular pressure by micromanometer provided end-diastolic pressure (P) area (A) relations during initiation and conclusion of cardiopulmonary bypass. Curve fitting to the equation P=alphae(betaA) defined the ventricular stiffness constant, beta. Changes in beta and clinical correlations were examined. Ventricular stiffness increased after bypass in patients with complete pre-bypass and post-bypass data (n =11, P=0.023, mixed models methodology). Pre-bypass beta correlated well with duration of chest tube (CT) drainage (r=0.90, n =16), net perioperative fluid balance (r=0.71, n=14), and length of stay (LOS) (r=0.81, n =16). CT duration and LOS also correlated significantly with post-bypass beta (r=0.77 for both, n=11), but insignificantly with preoperative catheterization pressures. CONCLUSIONS: Intraoperative beta predicts duration of CT drainage, net perioperative fluid balance, and LOS after the Fontan operation. These observations could improve risk stratification and clinical management of children at high-risk undergoing the Fontan operation.

Chest Tubes↗

PubMed2006

Left ventricular pacing site-timing optimization during biventricular pacing using a multi-electrode patch.

A 71-year-old man with class IV congestive heart failure and an infected pacemaker/implantable cardioverter defibrillator (ICD) underwent median sternotomy for removal of endocardial leads with a 15-mm vegetation. Cardiac output during biventricular pacing was optimized with an aortic flow probe, a multi-electrode left ventricular patch, and a randomized protocol assessing 54 combinations of pacing site and right ventricle-left ventricle delay. Results that were assessed with response surface methodology determined permanent epicardial lead position and timing. The difference between the best and worst site-timing combinations altered cardiac index by nearly 70%. This experience demonstrates potential importance of the epicardial approach to site-timing optimization for biventricular pacing.

Aged↗

PubMed2006

Load dependence of cardiac output in biventricular pacing: left ventricular volume overload in pigs.

OBJECTIVE: Previous work from our laboratory has demonstrated that optimization of biventricular pacing is load dependent. Cardiac output was maximized with a ventricular-ventricular delay of +40 milliseconds (right ventricle-first pacing) during right ventricular pressure overload and with a ventricular-ventricular delay of -40 milliseconds (left ventricle-first pacing) during right ventricular volume overload. We hypothesized that a model of left ventricular volume overload would also have specific timing requirements during biventricular pacing for optimization of cardiac output. METHODS: After median sternotomy in 6 anesthetized pigs, complete heart block was induced by ethanol ablation. A conduit was grafted from the left ventricle to the left atrium to produce left ventricular volume overload. An ultrasonic flow probe was placed around the conduit to measure retrograde flow that averaged 50% of cardiac output. During epicardial atrial tracking DDD biventricular pacing, atrioventricular delay was varied between 60 and 270 milliseconds in 30-millisescond increments for 20-second intervals. After determination of optimum atrioventricular delay, ventricular-ventricular delay was varied in 20-millisecond increments from +80 to -80 milliseconds for 20-second intervals. RESULTS: Ventricular-ventricular delays had no significant effect on cardiac output with the graft clamped (control). With the graft unclamped, however, there was a statistically significant (P = .0001 by repeated-measures analysis of variance) trend toward higher cardiac output with right ventricle-first pacing. CONCLUSIONS: Right ventricle-first pacing in swine significantly increased cardiac output during acute left ventricular volume overload, but not during the control state. Understanding load-specific pacing requirements will facilitate the development of perioperative temporary biventricular pacing for acute heart failure.

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