Effects of sildenafil citrate (Viagra) combined with nitrate on the heart.

BACKGROUND: Sildenafil citrate (Viagra) is indicated for the treatment of erectile dysfunction. Large and sudden decreases in systemic blood pressure were reported in a substantial number of patients taking sildenafil citrate combined with nitroglycerin. We studied the effect of sildenafil citrate on the relationship between changes in systemic blood pressure and coronary blood flow. METHODS AND RESULTS: Healthy male beagles were used to assess systemic blood pressure, pulmonary arterial pressure, and flow in the left circumflex artery (in which a critical stenosis was established) and left anterior descending coronary artery. After measurement of the hemodynamic variables, 2 mg/kg sildenafil citrate was administered via a nasogastric tube. Hemodynamic changes were monitored for 1 hour. Subsequently, the acute effect of nitrate combined with sildenafil citrate was studied by the bolus injection of 0.2 mg isosorbide dinitrate before and after sildenafil citrate. Systemic blood and pulmonary arterial pressures and circumflex flow did not change during this study; however, left anterior descending coronary arterial flow increased from 16.0+/-5.8 to 24.6+/-8.7 mL/min 1 hour after administration of sildenafil citrate. The prolongation of systemic blood pressure decrease and the circumflex flow decrement induced by isosorbide dinitrate after sildenafil citrate were significantly larger and longer than those before sildenafil citrate. CONCLUSIONS: Sildenafil citrate had the effect of vasodilation in a normal coronary artery; however, a combined effect with nitrate resulted in large and protracted decreases in systemic blood pressure and coronary blood flow in vessels with critical stenosis.

Independent association of high blood pressure and aortic atherosclerosis: A population-based study.

BACKGROUND: Atherosclerosis of the thoracic aorta is associated with stroke. The association between hypertension, a major risk factor for stroke, and aortic atherosclerosis has not been determined in the general population. METHODS AND RESULTS: Transesophageal echocardiography was performed in 581 subjects, a random sample of the Olmsted County (Minnesota) population aged >/=45 years participating in the Stroke Prevention: Assessment of Risk in a Community (SPARC) study. Blood pressure was assessed by multiple office measurements and 24-hour ambulatory blood pressure monitoring. The association between blood pressure variables and aortic atherosclerosis was evaluated by multiple logistic regression, adjusting for other associated variables. Among subjects with atherosclerosis, blood pressure variables associated with complex aortic atherosclerosis (protruding plaques >/=4 mm thick, mobile debris, or ulceration) were determined. Age and smoking history were independently associated with aortic atherosclerosis of any degree (P:

Frequency of atrial septal aneurysms in patients with cerebral ischemic events.

BACKGROUND: Atrial septal aneurysm (ASA) is a putative risk factor for cardioembolism. However, the frequency of ASA in the general population has not been adequately determined. Therefore, the frequency in patients with cerebral ischemic events, compared with the frequency in the general population, is poorly defined. We sought to determine the frequency of ASA in the general population and to compare the frequency of ASA in patients with cerebral ischemic events with the frequency in the general population. METHODS AND RESULTS: The frequency of ASA in the population was determined in 363 subjects, a sample of the participants in the Stroke Prevention: Assessment of Risk in a Community study (control subjects), and was compared with the frequency in 355 age- and sex-matched patients undergoing transesophageal echocardiography in search of a cardiac source of embolism after a focal cerebral ischemic event. The proportion with ASA was 7.9% in patients versus 2.2% in control subjects (P=0.002; odds ratio of ASA, 3.65; 95% CI, 1.64 to 8.13, in patients versus control subjects). Patent foramen ovale (PFO) was detected with contrast injections in 56% of subjects with ASA. The presence of ASA predicted the presence of PFO (odds ratio of PFO, 4.57; 95% CI, 2.18 to 9.57, in subjects with versus those without ASA). In 86% of subjects with ASA and cerebral ischemia, transesophageal echocardiography did not detect an alternative source of cardioembolism other than an associated PFO. CONCLUSIONS: The prevalence of ASA based on this population-based study is 2.2%. The frequency of ASA is relatively higher in patients evaluated with transesophageal echocardiography after a cerebral ischemic event. ASA is frequently associated with PFO, suggesting paradoxical embolism as a mechanism of cardioembolism. In patients with cerebral ischemia and ASA, ASA (with or without PFO) commonly is the only potential cardioembolic source detected with transesophageal echocardiography.

Echocardiographic assessment of the left atrial appendage.

The left atrial (LA) appendage is a common source of cardiac thrombus formation associated with systemic embolism. Transesophageal echocardiography allows a detailed evaluation of the structure and function of the appendage by two-dimensional imaging and Doppler interrogation of appendage flow. Specific flow patterns, reflecting appendage function, have been characterized for normal sinus rhythm and various abnormal cardiac rhythms. Appendage dysfunction has been associated with LA appendage spontaneous echocardiographic contrast, thrombus formation and thromboembolism. These associations have been studied extensively in patients with atrial fibrillation or atrial flutter, in patients undergoing cardioversion of atrial arrhythmias and in patients with mitral valve disease. The present review summarizes the literature on the echocardiographic assessment of LA appendage structure, function and dysfunction, which has become an integral part of the routine clinical transesophageal echocardiographic examination.

Intraoperative evaluation of mitral valve regurgitation and repair by transesophageal echocardiography: incidence and significance of systolic anterior motion.

OBJECTIVE: This study was designed to delineate the utility and results of intraoperative transesophageal echocardiography in the evaluation of patients undergoing mitral valve repair for mitral regurgitation. BACKGROUND: Mitral valve reconstruction offers many advantages over prosthetic valve replacement. Intraoperative assessment of valve competence after repair is vital to the effectiveness of this procedure. METHODS: Intraoperative transesophageal echocardiography was performed in 143 patients undergoing mitral valve repair over a period of 23 months. Before and after repair, the functional morphology of the mitral apparatus was defined by two-dimensional echocardiography; Doppler color flow imaging was used to clarify the mechanism of mitral regurgitation and to semiquantitate its severity. RESULTS: There was significant improvement in the mean mitral regurgitation grade by composite intraoperative transesophageal echocardiography after valve repair (3.6 +/- 0.8 to 0.7 +/- 0.7; p less than 0.00001). Excellent results from initial repair with grade less than or equal to 1 residual mitral regurgitation were observed in 88.1% of patients. Significant residual mitral regurgitation (grade greater than or equal to 3) was identified in 11 patients (7.7%); 5 underwent prosthetic valve replacement, 5 had revision of the initial repair and 1 patient had observation only. Of the 100 patients with a myxomatous mitral valve, the risk of grade greater than or equal to 3 mitral regurgitation after initial repair was 1.7% in patients with isolated posterior leaflet disease compared with 22.5% in patients with anterior or bileaflet disease. Severe systolic anterior motion of the mitral apparatus causing grade 2 to 4 mitral regurgitation was present in 13 patients (9.1%) after cardiopulmonary bypass. In 8 patients (5.6%), systolic anterior motion resolved immediately with correction of hyperdynamic hemodynamic status, resulting in grade less than or equal to 1 residual mitral regurgitation without further operative intervention. Transthoracic echocardiography before hospital discharge demonstrated grade less than or equal to 1 residual mitral regurgitation in 86.4% of 132 patients studied. A significant discrepancy (greater than 1 grade) in residual mitral regurgitation by predischarge transthoracic versus intraoperative transesophageal echocardiography was noted in 17 patients (12.9%). CONCLUSIONS: Transesophageal echocardiography is a valuable adjunct in the intraoperative assessment of mitral valve repair.

Aortic valve sclerosis and aortic atherosclerosis: different manifestations of the same disease? Insights from a population-based study.

OBJECTIVES: The aim of this study was to examine the association between atherosclerosis risk factors, aortic atherosclerosis and aortic valve abnormalities in the general population. BACKGROUND: Clinical and experimental studies suggest that aortic valve sclerosis (AVS) is a manifestation of the atherosclerotic process. METHODS: Three hundred eighty-one subjects, a sample of the Olmsted County (Minnesota) population, were examined by transthoracic and transesophageal echocardiography. The presence of AVS (thickened valve leaflets), elevated transaortic flow velocities and aortic regurgitation (AR) was determined. The associations between atherosclerosis risk factors, aortic atherosclerosis (imaged by transesophageal echocardiography) and aortic valve abnormalities were examined. RESULTS: Age, male gender, body mass index (odds ratio [OR]: 1.07 per kg/m(2); 95% confidence interval [CI]: 1.02 to 1.12), antihypertensive treatment (OR: 1.93; CI: 1.12 to 3.32) and plasma homocysteine levels (OR: 1.89 per twofold increase; CI: 0.99 to 3.61) were independently associated with an increased risk of AVS. Age, body mass index and pulse pressure (OR: 1.21 per 10 mm Hg; CI: 1.00 to 1.46) were associated with elevated (upper quintile) transaortic velocities, whereas only age was independently associated with AR. Sinotubular junction sclerosis (p = 0.001) and atherosclerosis of the ascending aorta (p = 0.03) were independently associated with AVS and elevated transaortic velocities, respectively. CONCLUSIONS: Atherosclerosis risk factors and proximal aortic atherosclerosis are independently associated with aortic valve abnormalities in the general population. These observations suggest that AVS is an atherosclerosis-like process involving the aortic valve.

Remote telemedical interpretation of neonatal echocardiograms: impact on clinical management in a primary care setting.

OBJECTIVE: The purpose of this study was to evaluate the utility of telemedical echocardiographically assisted neonatal cardiovascular evaluation in a primary care setting. BACKGROUND: Neonates with congenital heart disease are frequently born far from pediatric subspecialty centers and can be clinically unstable at presentation. Recent advances in telecommunication technology have made it possible to transmit echocardiographic images over long distances. This technology may be beneficial to newborns with heart defects who are born in primary care centers. METHODS: A retrospective review of all telemedical echocardiograms obtained from neonates (aged 1 day to 30 days) was performed. A telemedical link was created using a T-1 transmission line and a standard voice telephone line between the Mayo Clinic, Rochester, Minnesota (pediatric cardiology site), and the Altru Clinic, Grand Forks, North Dakota (primary care site), which is a general pediatric practice 400 miles from Rochester. Neonates with possible cardiac disorders were identified by the general pediatricians, who then requested telemedical echocardiography. RESULTS: The 133 neonates had 161 T-1 echocardiograms. Median patient age was two days (range, one day to 29 days). One hundred thirty-two of 133 initial echocardiograms (99%) were obtained because of urgent indications. Transmitted images provided adequate diagnostic information in all patients. Seventy-nine neonates (59%) had a change in medical management or required cardiology follow-up. An immediate change in management occurred in 32 patients (24%), including seven in whom emergency transfer was either arranged or avoided. CONCLUSIONS: Telemedical echocardiography provides accurate diagnostic data in neonates. Rapid telediagnosis facilitates appropriate care of sick neonates with possible congenital heart disease in the primary care setting. Unnecessary long-distance transfers can be avoided with this technology.

Functional anatomy of mitral regurgitation: accuracy and outcome implications of transesophageal echocardiography.

OBJECTIVES: This study was performed to determine the accuracy and outcome implications of mitral regurgitant lesions assessed by echocardiography. BACKGROUND: In patients with mitral regurgitation (MR), valve repair is a major incentive to early surgery and is decided on the basis of the anatomic mitral lesions. These lesions can be observed easily with transesophageal echocardiography (TEE), but the accuracy and implications for outcome and clinical decision-making of these observations are unknown. METHODS: In 248 consecutive patients operated on for MR, the anatomic lesions diagnosed with TEE were compared with those observed by the surgeon and those seen on 216 transthoracic echocardiographic (TTE) studies, and their relationship to postoperative outcome was determined. RESULTS: Compared with surgical diagnosis, the accuracy of TEE was high: 99% for cause and mechanism, presence of vegetations and prolapsed or flail segment, and 88% for ruptured chordae. Diagnostic accuracy was higher for TEE than TTE for all end points (p < 0.001), but the difference was of low magnitude (<10%) except for mediocre TTE imaging or flail leaflets (both p < 0.001). The type of mitral lesions identified by TEE (floppy valve, restricted motion, functional lesion) were determinants of valve repairability and postoperative outcome (operative mortality and long-term survival; all p < 0.001) independent of age, gender, ejection fraction and presence of coronary artery disease. CONCLUSIONS: Transesophageal echocardiography provides a highly accurate anatomic assessment of all types of MR lesions and has incremental diagnostic value if TTE is inconclusive. The functional anatomy of MR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome. Therefore, the mitral lesions assessed by echocardiography represent essential information for clinical decision making, particularly for the indication of early surgery for MR.

Predictors of cerebrovascular events and death among patients with valvular heart disease: A population-based study.

BACKGROUND AND PURPOSE: There is little population-based information on cerebrovascular events and survival among valvular heart disease patients. We used the Kaplan-Meier product-limit method and the Cox proportional hazards model to determine rates and predictors of cerebrovascular events and death among valve disease patients. METHODS: This population-based historical cohort study in Olmsted County, Minnesota, reviewed residents with a first echocardiographic diagnosis of mitral stenosis (n=19), mitral regurgitation (n=528), aortic stenosis (n=140), and aortic regurgitation (n=106) between 1985 and 1992. RESULTS: During 2694 person-years of follow-up, 98 patients developed cerebrovascular events and 356 died. Compared with expected numbers, these observations are significantly elevated, with standardized morbidity ratio of 3.2 (95% CI, 2.6 to 3.8) and 2. 5 (95% CI, 2.2 to 2.7), respectively. Independent predictors of cerebrovascular events were age, atrial fibrillation, and severe aortic stenosis. The risk ratio of severe aortic stenosis was 3.5 (95% CI, 1.4 to 8.6), with atrial fibrillation conferring greater risk at younger age. Predictors of death were age, sex, cerebrovascular events, ischemic heart disease, and congestive heart failure, the greatest risk being among those with both congestive heart failure and cerebrovascular events (risk ratio=8.8; 95% CI, 5. 8 to 13.4). Valve disease type and severity were not independent determinants of death. CONCLUSIONS: The risk of cerebrovascular events and death among patients with valve disease remains high. Age, atrial fibrillation, and severe aortic stenosis are independent predictors of cerebrovascular events, and age, sex, cerebrovascular events, congestive heart failure, and ischemic heart disease are independent predictors of death in these patients.

Patent foramen ovale in patients with cerebral infarction. A transesophageal echocardiographic study.

OBJECTIVES: To determine the frequency of patent foramen ovale (PFO) among various subtypes of cerebral infarction. To determine whether any historical or clinical characteristics predict the presence or absence of PFO in these patients. DESIGN: Comorbidity and infarct subtype study. SETTING: Referral-based study. PATIENTS: One hundred sixteen patients with cerebral infarction consecutively referred for transesophageal echocardiography during a 6-month period. MAIN OUTCOME MEASURES: Infarct subtype classification was made using a clinical and radiographic diagnostic rubric similar to that used by the Stroke Data Bank of the National Institute of Neurological Diseases and Stroke. The frequency of various risk factors and clinical characteristics in patients with and in those without PFO and the frequency of PFO in patients with various infarct subtypes were compared (chi 2 or Fisher exact tests). RESULTS: Patent foramen ovale was detected in 37 patients (32%). Mean age was similar in those with (60 years) and those without (64 years) PFO. Patent foramen ovale was more frequent among men (39%) than women (20%, P = .03). Patients with PFO had a lower frequency of atrial fibrillation, diabetes mellitus, hypertension, and peripheral vascular disease compared with those without PFO. There was no difference in frequency of the following characteristics in patients with PFO compared with those without PFO: pulmonary embolus, chronic obstructive pulmonary disease, pulmonary hypertension, peripheral embolism, prior cerebral infarction, nosocomial cerebral infarction, Valsalva maneuver at the same time of cerebral infarction, recent surgery, or hemorrhagic transformation of cerebral infarction. Patent foramen ovale was found in 22 (40%) of 55 patients with infarcts of uncertain cause and in 15 (25%) of 61 with infarcts of known cause (cardioembolic, 21%; large vessel atherostenosis, 25%; lacune, 40%) (P = .08). When the analysis was restricted to patients who underwent Valsalva maneuver, PFO with right to left or bidirectional shunt was found in 19 (50%) of 38 patients with infarcts of uncertain cause and in 6 (20%) of 30 with infarcts of known cause (P = .01). CONCLUSION: Although PFO was overrepresented in patients with infarcts of uncertain in our and other studies, it has a high frequency among patients with cerebral infarction of all types. The relation between PFO and stroke requires further study.

Mitral valve prolapse and the risk of stroke after initial cerebral ischemia.

Referral-based studies suggest that patients with cerebral ischemia and mitral valve prolapse are prone to recurrent cerebral ischemic events. Our purpose was to determine the risk of subsequent stroke in a population-based group of patients with ischemic stroke or TIA and mitral valve prolapse. From 1975 through 1990, 49 residents of Olmsted County, MN, had an initial ischemic stroke or TIA and echocardiographically diagnosed mitral valve prolapse. Risk of subsequent stroke in this cohort was compared with the age- and sex-adjusted rates of recurrent stroke after initial cerebral ischemia in the Rochester, MN, population. Mean age of the patients was 72 years. Thirty-one (63%) were women. Nine had subsequent stroke (5.5 per 100 person-years). For Rochester patients who had initial ischemic stroke in the period 1975 through 1984, 10.72 recurrent strokes were expected (relative risk, 0.84; 95% confidence limits, 0.38 to 1.59). For Rochester patients with initial ischemic stroke or TIA in the period 1975 through 1979, 12.31 recurrent strokes were expected (relative risk, 0.73; 95% confidence limits, 0.33 to 1.39). There is no evidence of increased subsequent stroke risk among patients with initial episodes of cerebral ischemia and mitral valve prolapse relative to the age- and sex-adjusted recurrent stroke rates in the community.

Thromboembolic complications after electrical cardioversion in patients with atrial flutter.

PURPOSE: To determine the incidence of thromboembolic complications after cardioversion in patients with atrial flutter. SUBJECTS AND METHODS: We reviewed 615 electrical cardioversions performed electively in 493 patients with atrial flutter. Embolic complications were evaluated during the 30 days after cardioversion. Follow-up data were obtained by follow-up visits and by contacting the treating physician. RESULTS: Anticoagulants had been administered in 415 cardioversions (67%). Cardioversion was successful in 570 procedures (93%). Three embolic events (in 3 patients) occurred in the 30 days after 550 successful cardioversions with completed follow-up (0.6% of successful procedures; 95% confidence interval, 0.1% to 1.6%). Two of the 3 patients had not been anticoagulated, whereas the third patient had subtherapeutic oral anticoagulation. No embolic event occurred in procedures performed with adequate anticoagulation. The incidence of embolism in patients regardless of subtherapeutic anticoagulation was 1% (3 of 303 successful cardioversions). CONCLUSIONS: We observed a low (0.6%) incidence of postcardioversion thromboembolic complications in patients with atrial flutter. Embolic events did not occur in patients with adequate anticoagulation.

Transesophageal echocardiography: state-of-the art and future directions.

Transesophageal echocardiography complements transthoracic examination in 5-10% of patients referred to the echocardiographic laboratory. Clinical indications for performing this procedure are continually evolving. The semi-invasive nature of this procedure necessitates that it be judiciously used and that trained personnel undertake the procedure. Complications of the procedure need to be kept in mind. Future directions in the development of this technology involve newer, multiplanar, multifrequency transducers, digital archiving and retrieval, wide-field imaging, and 3-dimensional reconstruction. For the present, transthoracic echocardiography must remain the primary echocardiographic window imaging the heart, with defined clinical applications for transesophageal echocardiography.

Transesophageal echocardiography in critically ill patients.

The feasibility, safety and clinical impact of transesophageal echocardiography were evaluated in 51 critically ill intensive care unit patients (28 men and 23 women; mean age 63 years) in whom transthoracic echocardiography was inadequate. At the time of transesophageal echocardiography, 30 patients (59%) were being mechanically ventilated. Transesophageal echocardiography was performed without significant complications in 49 patients (96%), and 2 patients with heart failure had worsening of hemodynamic and respiratory difficulties after insertion of the transesophageal probe. The most frequent indication, in 25 patients (49%), was unexplained hemodynamic instability. Other indications included evaluation of mitral regurgitation severity, prosthetic valvular dysfunction, endocarditis, aortic dissection and potential donor heart. In 30 patients (59%), transesophageal echocardiography identified cardiovascular problems that could not be clearly diagnosed by transthoracic echocardiography. In the remaining patients, transesophageal echocardiography permitted confident exclusion of suspected abnormalities because of its superior imaging qualities. Cardiac surgery was prompted by transesophageal echocardiographic findings in 12 patients (24%) and these findings were confirmed at operation in all. Therefore, transesophageal echocardiography can be safely performed and has a definite role in the diagnosis and expeditious management of critically ill cardiovascular patients.

Evaluation of coronary flow reserve in hypertensive patients by dipyridamole transesophageal doppler echocardiography.

This study evaluates the coronary flow reserve (CFR) in hypertensive patients with and without left ventricular (LV) hypertrophy. CFR was assessed by transesophageal Doppler echocardiography in 15 normal subjects (group I), 21 hypertensive patients without LV hypertrophy (group II), and 27 hypertensive patients with LV hypertrophy (group III). All hypertensive patients were complaining of typical anginal pain and had normal coronary angiograms. The sample volume was placed at the bifurcation of the left main and left anterior descending coronary arteries. Coronary blood flow velocities were evaluated at rest, 2 minutes after dipyridamole infusion, and 2 minutes after intravenous aminophylline. The ratios of dipyridamole to rest peak diastolic and systolic velocities were considered as indexes of CFR. Peak diastolic velocity ratio was significantly lower in group III than in groups I and II (1.6 +/- 0.2, 2.7 +/- 0.4, and 2.1 +/- 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak systolic velocity ratio was significantly lower in group III than in groups I and II (1.7 +/- 0.3, 2.8 +/- 0.3, and 2.1 +/- 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak diastolic velocity ratio was inversely related to systolic blood pressure, diastolic blood pressure, and LV mass index (r = -0.48, -0. 51, and -0.37 respectively) in hypertensive patients. It is concluded that CFR is significantly impaired in hypertensive patients, especially those with LV hypertrophy, compared with healthy subjects. The degree of impairment of CFR is related to LV mass index.

Value and limitations of two-dimensional echocardiography in predicting myocardial infarct size.

To investigate the quantitative relations between the severity of regional wall motion abnormalities and segmental infarct size and between the severity of overall left ventricular dysfunction and global infarct size, a clinicopathologic study was undertaken of 30 patients who had a 2-dimensional (2-D) echocardiogram within 7 days before death. The severity of regional wall motion abnormalities was graded for each segment with a 2-D echocardiographic 14-segment model. The severity of global left ventricular dysfunction was calculated as the mean of the visualized regional wall motion scores. On pathologic examination of autopsy specimens, segmental infarct size was estimated as a percentage of the segmental cross-sectional area. The global infarct size was expressed as a percentage of the total left ventricular mass. At the segmental level, regional wall motion score was positively correlated (r = 0.53) with the segmental infarct size. The sensitivity and specificity of detecting infarcted segments by abnormal wall motion scores were 81 and 71%, respectively. All dyskinetic segments revealed infarct size of greater than or equal to 10%. The wall motion score index was positively correlated (r = 0.52) with the global infarct size. The mean global infarct size was 7% for the 8 patients with a wall motion score index of less than 2, which was significantly lower than the mean of 27% for the 22 patients with a wall motion score index of greater than or equal to 2 (p less than 0.001). A 2-D echocardiogram is sensitive and specific in detecting infarcted segments and can be useful in quantitating myocardial damage after myocardial infarction.

Effect of volume reduction on mitral annular diastolic velocities in hemodialysis patients.

The effect of volume reduction on various diastolic Doppler parameters of left ventricular filling was assessed in 13 patients before and after hemodialysis. Volume reduction decreased early diastolic mitral annular velocities to a lesser extent than early diastolic mitral inflow velocities.

Left atrial appendage flow velocities in subjects with normal left ventricular function.

The objectives of this study were to establish reference values and define the determinants of left atrial appendage (LAA) flow velocities in the general population. LAA flow velocities (contraction and filling velocities) were assessed by transesophageal echocardiography in 310 subjects aged > or = 45 years, sampled from the population-based Stroke Prevention: Assessment of Risk in a Community study. All subjects were in sinus rhythm, with preserved left ventricular systolic function (ejection fraction > or = 50%), and without valvular disease. Values of LAA contraction and filling velocities were established for various age groups in the population. Age was negatively associated with LAA contraction and filling velocities, which decreased by 4.1 cm/s (p < 0.001) and 2.0 cm/s (p < 0.01) for every 10 years of age, respectively. Contraction velocities were 5 cm/s higher in men than in women (p < 0.05). After adjusting for age and sex, heart rate was independently associated with LAA contraction velocities (p < 0.001; nonlinear association). Body surface area, left atrial size, left ventricular mass index, and a history of previous cardiac disease or hypertension showed no significant association with LAA flow velocities (p > 0.05). Furthermore, detailed analysis of 24-hour ambulatory blood pressure data (available in 253 subjects) showed no association between various blood pressure parameters (systolic and diastolic blood pressure, out-of-bed and in-bed measurements) and LAA flow velocities (all p > 0.05). In summary, the present study establishes the reference values for LAA flow velocities in a large sample of the general population. LAA flow velocities progressively decline with age in subjects with preserved left ventricular systolic function.

Silent myocardial ischemia.

ST-segment depression in the absence of symptoms is now a well-defined abnormality in patients with coronary artery disease. ST-segment depression without the occurrence of angina is a marker for myocardial perfusion defects and ischemia. During 24-hour recordings, most episodes of ischemia in patients with coronary artery disease are silent and occur with relatively normal heart rates. The combination of silent ischemia and ischemia associated with angina is referred to as total ischemic burden. Silent ischemia is prognostically important for identifying patients in whom subsequent myocardial events may develop. The episodes of silent ischemia, and thus total ischemic burden, can be reduced by standard antianginal therapy, a measure that may have a favorable influence on patient outcome. Proof that reduction of the total ischemic burden actually improves outcome, however, is not yet available.

Wide-field transesophageal echocardiographic tomography: feasibility study.

In this report, we describe our initial investigation of wide-field ultrasonic cardiothoracic tomography utilizing a transesophageal transducer. Examination included manual rotation of an esophageal transducer 180 to 360 degrees in order to visualize contiguous related structures. Consecutive sector views were photographed and then incorporated into a digital graphics computer for smoothing. This feasibility study introduces the concept of wide-field transesophageal cardiothoracic ultrasound tomography, which holds promise for tomographic depiction of cardiothoracic and mediastinal anatomy.