Measuring aortic valve coaptation surface area using three-dimensional transesophageal echocardiography.

BACKGROUND: As aortic valve (AV) repairs become more sophisticated, surgeons need increasingly detailed information about the structure and function of this valve. Unlike two-dimensional transesophageal echocardiography (2D-TEE), using three-dimensional (3D)-TEE makes it possible to image the entire AV. We hypothesized that measuring coaptation surface area (CoapSA) would be feasible and reproducible, and CoapSA would decrease in patients with aortic insufficiency. METHODS: We developed a new technique to calculate the AV-CoapSA using 3D-TEE. We measured the coaptation surfaces between the right coronary cusp/left coronary cusp, right coronary cusp/non-coronary cusp, and left coronary cusp/non-coronary cusp in ten normal AVs and ten AVs with moderate-severe aortic insufficiency (AI). Since computer models have previously shown that CoapSA is trapezoidal, we used the formula: trapezoid area = length × (medial coaptation height + lateral coaptation height)/2. The total CoapSA was calculated by adding all three areas. To adjust for valve size, we indexed the value to the diameter of the ventricular aortic junction (VAJ). Measurements were performed by two observers. RESULTS: The intra-observer correlation was 0.84 for one observer (P < 0.0001) and 0.93 for the other (P < 0.0001). The inter-observer correlation was 0.87 (P < 0.0001). In normal valves, the CoapSA [mean total (standard deviation)] was significantly greater than in the insufficient valves [1.61 (0.31) cm(2) vs 1.03 (0.22) cm(2), respectively; P < 0.001]. After indexing for the VAJ diameter, the total CoapSA remained significantly greater in normal valves than in insufficient valves. CONCLUSION: In this proof of concept study, we present a new and innovative technique to measure AV-CoapSA using 3D-TEE. It is reproducible and shows decreased CoapSA in patients with AI. Coaptation surface area may provide insight into mechanisms of AI and may have predictive value following AV repair.

Minimally Invasive Coronary Artery Bypass Grafting in a Patient With Chronic Tracheostoma: Alternative to Reduce Sternal Wound Complication Risk.

Patients with chronic tracheostoma present a challenge when they require coronary bypass surgery due to an elevated risk of sternal wound infections (SWI). Minimally invasive coronary artery bypass grafting (MICS CABG) is a robust technique that allows complete surgical revascularization while mitigating the risks of sternal complications and functional decline associated with sternotomy. In such patients at elevated risk for SWI, MICS CABG may represent a viable revascularization strategy to avoid sternotomy. Here, we present a case of a frail, comorbid patient with a chronic tracheostomy and symptomatic multivessel coronary artery disease not amenable to percutaneous therapy referred for MICS CABG.

Proximal isovelocity surface area should be routinely measured in evaluating mitral regurgitation: a core review.

The proximal isovelocity surface area (PISA) measurement, also known as the "flow convergence" method, can be used in echocardiography to estimate the area of an orifice through which blood flows. It has many applications, but this review focuses only on its use in the intraoperative evaluation of mitral regurgitation. In that setting, PISA provides a quantitative assessment of the severity of mitral regurgitation and it is useful in clinical decision-making in the operating room. In this review, I discuss the physical principles behind the PISA method, along with the various mathematical formulas used to calculate the effective mitral regurgitant orifice area, the regurgitant volume, and the regurgitant fraction. A step-by-step approach is presented and illustrated with graphic and video demonstrations. Finally, I will discuss the various limitations and technical considerations of PISA measurement in the operating room.

Right heart obstruction from a balloon-like sinus of Valsalva aneurysm in a patient with Down syndrome.

A 40-year-old man with Down syndrome presented with right heart failure. He was markedly obese and had severe developmental delay. There was marked edema and an early diastolic sound. Transthoracic echocardiography suggested a right heart mass. Transesophageal echocardiography revealed an unruptured balloon-like sinus of Valsalva aneurysm within the right atrium that obstructed the tricuspid orifice. The patient died in hospital of mixed obstructive and/or septic shock.

Successful surgical repair of ventricular double rupture.

Cardiac rupture represents a catastrophic complication of myocardial infarction with an exceedingly high mortality rate. In rare instances, a myocardial infarction can be complicated by 2 separate forms of rupture. The most common form of ventricular double rupture consists of free wall rupture in association with ventricular septal rupture. The present case provides an example of survival following this form of ventricular double rupture and emphasizes the importance of prompt clinical recognition followed by urgent surgical repair.

Survey of the members of the cardiovascular section of the Canadian Anesthesiologists' Society on the use of perioperative transesophageal echocardiography - a brief report.

PURPOSE: Transesophageal echocardiography (TEE) is a useful diagnostic and monitoring tool in the operating room. In the United States, an increasing number of centres are training anesthesiologists to preform intraoperative TEE. In Canada, TEE has been slow to gain acceptance as an intraoperative monitor and little information is available on its use by the anesthesiologists across the country. METHODS: We surveyed all members of the cardiovascular section of the Canadian Anesthesiologists' Society, to find out how many perform TEE, how they acquired their skills and how they use TEE in their practice. RESULTS: The response rate was 48.4%. Most respondents were Canadian-trained cardiac anesthesiologists working in university centres. 91% of respondents stated that their centres offer intraoperative TEE services. Of those services, 35.1% were provided by anesthesiologists only, 13% by cardiologists only, and 51.9% by both. 53.8% of respondents have certification in intraoperative TEE (NBE/SCA, ASE or Provincial College). 90% of respondents use equipment that is less than five years old and multiplane probes are used by almost everyone. There was strong support for Canadian-based continuing medical education events in perioperative TEE. CONCLUSION: TEE appears to be available in most cardiac centres in Canada and anesthesiologists are actively involved in providing intraoperative TEE services, using state-of-the-art equipment. Many anesthesiologists have formal training in TEE.

Is PA-PWRmax truly a preload-independent index of myocardial contractility in anesthetized humans?

This study tested the hypothesis that the preload-adjusted maximal power index (PA-PWRmax) is a load-independent index of human myocardial contractility. Based on the ventricular pressure-volume relationship and derived from stroke work, the index is the product of instantaneous ventricular pressure and volume changes, divided by a correction term of end-diastolic volume (EDV2) or end-diastolic area (EDA3/2) to adjust for preload effects. Echocardiographic measures of instantaneous ventricular area change may be used to obtain PA-PWRmax noninvasively. We prospectively evaluated 28 human subjects undergoing cardiac evacuation before cardiopulmonary bypass procedures. Continuous peripheral arterial pressure, pulmonary arterial pressure, and echocardiographic views of the left ventricle in the transgastric short-axis view were recorded. Simultaneously gated instantaneous fractional shortening (FS) and PA-PWRmax indices were calculated, with FS = (EDA - ESA)/EDA and PA-PWRmax = [MAP (EDA - ESA)]/ EDA3/2, where ESA = end-systolic area and MAP = instantaneous mean arterial pressure. FS decreased uniformly with cardiac evacuation and decreasing pulmonary artery diastolic pressure (t = -5.4; 95% confidence interval, -10 to -0.046; p < 0.001), as did PA-PWRmax (t = -5.8; 95% confidence interval, -2.25 to -1.08; p < 0.001). FS and PA-PWRmax showed a strong downward correlation (r = 0.81). Unlike previous studies of autonomically denervated animals, our study did not find PA-PWRmax to be preload independent, perhaps because of the instantaneous homeostatic mechanisms of the human autonomic nervous system linking contractility to loading conditions.