Intraoperative transesophageal echocardiography during valve replacement surgery. A review.

Intraoperative transesophageal echocardiography (IOTEE) has become an important diagnostic and monitoring tool in the operating theatre during cardiac and noncardiac operations. However, its routine application during valve replacement operations has not received universal recognition. The cumulative experience, brought up in this review, shows that IOTEE is invaluable during valve replacement operations. It has an important role in the consolidation of operative strategy, although it is generally better to obtain all the anatomical and physiological data and the resultant operative strategy in advance, outside the operating room environment. Important data influencing the operative plan has been reported in 3-29% of operations in various studies. The postpump IOTEE is also essential for numerous reasons: it can rule out important misfortunes, such as leaflet immobilization or perivalvular leak, leaky bioprosthesis or coronary obstruction due to valve struts, and is responsible for second pump-run in 3-6% of cases; it is essential in monitoring the deairing process; it provides the surgeon and the anesthesiologist data on biventricular function and volume and exclusion of dynamic left ventricular outflow tract obstruction, and, therefore, guides pharmacotherapy, volume handling and mechanical assistance, including intra-aortic balloon pump indication and location. In conclusion, IOTEE is an essential tool in patients undergoing valve replacement operations, and should be used on a standard basis.

Initial clinical experience with a hand-held device (Thrombocheck) for the detection of bileaflet prosthetic valve malfunction.

BACKGROUND AND AIM OF THE STUDY: Early recognition of subclinical prosthetic valve malfunction may promote early treatment and avoidance of serious complications. Echocardiography cannot be applied on a daily basis; thus, a hand-held device (Thrombocheck) which is capable of detecting subtle changes in the acoustic sounds of prosthetic valve has been developed for the routine home monitoring of heart valve function. Herein is reported the authors' initial clinical experience with this device. METHODS: Seventy-one consecutive patients with one or more bileaflet prosthetic mechanical valves at any position were assessed both by transthoracic echocardiography (TTE) and by Thrombocheck. These patients attended the authors' clinic for either routine echocardiography (n = 62) or for the detection of prosthetic valve malfunction (n = 9). Cinefluoroscopy and transesophageal echocardiography were used selectively to confirm prosthetic valve malfunction. The Thrombocheck was held for 1 min in the subxiphoid position perpendicular to the patient, and indicated either normal function (OK), abnormal function (Warning) or 'no signal'. RESULTS: The study patients had in total 82 bileaflet valves (47 mitral, 31 aortic, four tricuspid). Eight patients (11.3%) had a 'no signal' indication. Of the remaining 63 patients, 10 (15.9%) had a 'warning' alarm (eight patients had current abnormal leaflet motion, one patient had a recent history of abnormal leaflet motion, and one had no evidence of prosthetic valve malfunction). The sensitivity and specificity for detecting abnormal prosthetic valve malfunction were 90% and 98%, respectively. CONCLUSION: The Thrombocheck had an excellent sensitivity and specificity for the detection of prosthetic valve malfunction in a cohort of patients with bileaflet mechanical prosthetic heart valves.

Association between mitral annulus calcification and aortic atheroma: a prospective transesophageal echocardiographic study.

BACKGROUND AND PURPOSE: Although mitral annulus calcification (MAC) has been reported to be a significant independent predictor of stroke, no causative relationship was proven. It is also known that aortic atheroma (AA), especially those >/=5 mm thick and/or protruding and/or mobile are associated with stroke. This study was designed to determine whether an association exists between MAC and AA. METHODS: We prospectively evaluated the records of 279 consecutive patients who underwent transesophageal echocardiography (TEE) for various indications to measure the presence and characteristics of AA. The 105 patients in whom a diagnosis of MAC was made on transthoracic echocardiography (TTE) immediately preceding the TEE, were compared with 174 age-matched patients without MAC. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. We measured MAC thickness with two-dimensional-TTE in four-chamber view and AA thickness, protrusion and mobility with TEE. AA was defined as localized intimal thickening of >/=3 mm. A lesion was considered complex if there was plaque extending >/=5 mm into the aortic lumen and/or if it was protruding, mobile or ulcerated. RESULTS: No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the MAC group for prevalence of AA (91 vs. 44%, P<0.001), atheromas >/=5 mm thick (68 vs. 19%, P<0.001), protruding atheromas (44 vs. 15%, P<0.001), ulcerated atheromas (10 vs. 1%, P<0.001) and complex atheroma (74 vs. 22%, P<0.001). Sixty patients had MAC thickness >/=6 mm and 45<6 mm. AA thickness was significantly greater in the patients with a MAC thickness of >/=6 mm (6.1+/-2.8 vs. 5.0+/-2.6 mm, P=0.03). On multivariate analysis MAC, hypertension and age were the only independent predictors of AA (P=0.0001, 0.005 and 0.007, respectively). CONCLUSIONS: There is a significant association between the presence and severity of MAC and AA. MAC may be an important marker for atherosclerosis of the aorta. This association may explain in part the high prevalence of systemic emboli and stroke in patients with MAC.

Nonobstructive aortic valve calcium as a window to atherosclerosis of the aorta.

Aortic valve calcium without stenosis and mitral annulus calcium (MAC) are known to correlate with atherosclerotic risk factors. Recently, it has been reported that MAC is associated with atherosclerosis of the cardiovascular system, suggesting MAC as an atherosclerotic process by itself. Hence, the aim of the present study was to determine whether a similar association between aortic valve calcium and aortic atheroma exists. Ninety-six patients (54 men and 42 women, mean age 72 +/- 12 years) with aortic valve calcium who underwent transesophageal echocardiography (TEE) formed the study group. They were compared with 92 sex- and age-matched patients without aortic valve calcium who underwent TEE for the same indications during the same period. The presence and echocardiographic features of aortic atheromas were evaluated by TEE. No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the aortic valve calcium group for prevalence of aortic atheroma (86% vs 30%, p = 0.001). This significant trend was also consistent with the dimension and complexity of the atheromas. On multivariate analysis aortic valve calcium, and MAC were the only independent predictors of aortic atheroma (p = 0.0001, 0.006 respectively). We conclude that there is a significant association between the presence of aortic valve calcium and the presence and severity of aortic atheroma. Thus, aortic valve calcium may serve as a window to atherosclerosis of the aorta.

Significance of prominent atrial-wave and diastasis deflection in radionuclide diastolic volume curve during exercise in detection of coronary artery disease.

BACKGROUND: Exercise testing with multigated acquisition technetium radionuclide cineangiography (MUGA) is a useful modality that can discriminate systolic and diastolic performance in patients with ischemic heart disease. However, some patients may have abnormal left ventricular filling dynamics with normal regional and global systolic function. HYPOTHESIS: The purpose of the study was to assess exercise-induced diastolic dysfunction as expressed by a prominent atrial (A) wave or diastasis deflection at the left ventricular volume curve, in patients with different degrees of ischemic heart disease. METHODS: In all, 32 men and 7 women aged 35-70 years (mean 54 +/- 8.6 years) underwent MUGA at rest and during exercise for analysis of the radionuclide volume curve. Within 6 weeks, thallium-201 scintigraphy and coronary angiography were performed and the patients were categorized into three groups: (1) disease-free (n = 10), (2) single-vessel disease (> 50% stenosis) (n = 19), and (3) double-vessel disease or more (n = 10). A waves or diastasis deflections were compared among the groups. RESULTS: Significant differences (p < 0.01) were noted in A-wave deflection relative to peak diastolic volume curve during exercise (Aexe/T) between Group 1 and Groups 2 and 3. Group 1 manifested only a mild rise in A-wave deflection from rest (20.20 +/- 8.49%) to exercise (25.85 +/- 8.49%), whereas Groups 2 and 3 exhibited a significant increase from 25.89 +/- 9.55% and 28.40 +/- 12.6%, respectively, to 60.21 +/- 22.5% and 63.0 +/- 22.86%, respectively. Group 2 had a significantly (p < 0.05) higher maximal heart rate than Group 3. CONCLUSIONS: The addition of prominent A-wave or diastasis deflection to a normal systolic response during exercise testing with multigated radionuclide cineangiography might be a sensitive marker of coronary artery disease. The A wave represents diastolic dysfunction of the left ventricle, considered an early event in the ischemic cascade.

Sudden death among the Israeli civilian population during the Gulf War--incidence and mechanisms.

The Gulf War in January 1991 provided a unique opportunity to evaluate the influence of acute stress on the incidence of sudden cardiac death (SCD) in the Israeli civilian population. Pursuing this intriguing issue seemed warranted as we documented and reported a pronounced increase in the incidence of acute myocardial infarctions during that period. The purpose of the present study therefore was to document the incidence of SCD in different regions of Israel during a 10 day period preceding the Gulf War and a similar period following its onset, and to try to identify a possible correlation between the intensity of threat and the incidence of SCD. Sixty-eight cases during the Gulf War study period were compared to 213 cases in 5 control periods; overall 281 cases of SCD were documented. A rise in the incidence of SCD during the first 10 days of the war as compared to previous periods was noted but did not reach statistical significance. No correlation was demonstrated for SCD incidence among different regions in relation to the intensity of threat. Mechanisms by which acute stress precipitates an acute coronary syndrome are discussed, and an explanation for the lack of a statistically significant difference in SCD incidence is offered.