Echocardiography for assessing cardiac risk in patients having noncardiac surgery. Study of Perioperative Ischemia Research Group.

BACKGROUND: Cardiac complications after noncardiac surgery are a serious cause of illness and death. Echocardiography is being used before noncardiac surgery to assess risk for cardiac complications, but its role remains undefined. OBJECTIVE: To examine the prognostic value and operating characteristics of transthoracic echocardiography for assessing cardiac risk before noncardiac surgery. DESIGN: Prospective cohort study. SETTING: University-affiliated Veterans Affairs medical center. PATIENTS: 339 consecutive men who were known to have or were suspected of having coronary artery disease and were scheduled for major noncardiac surgery. MEASUREMENTS: Information from detailed histories, physical examinations, and electrocardiographic and laboratory studies was routinely collected. Transthoracic echocardiography was done before surgery to assess ejection fraction, wall motion abnormalities (reported as the wall motion score [range, 5 to 25 points]), and left ventricular hypertrophy. MAIN OUTCOME MEASURES: Postoperative ischemic events (cardiac-related death, nonfatal myocardial infarction, and unstable angina), congestive heart failure, and ventricular tachycardia. RESULTS: 10 patients (3%) had ischemic events; 26 (8%) had congestive heart failure; and 29 (8%) had ventricular tachycardia. No echocardiographic measurements were associated with ischemic events. In univariate analyses, an ejection fraction less than 40% was associated with all cardiac outcomes combined (odds ratio, 3.5 [95% CI, 1.8 to 6.7]), congestive heart failure (odds ratio, 3.0 [CI, 1.2 to 7.4]), and ventricular tachycardia (odds ratio, 2.6 [CI, 1.1 to 6.2]). In multivariable analyses that adjusted for known clinical risk factors, an ejection fraction less than 40% was a significant predictor of all outcomes combined (odds ratio, 2.5 [CI, 1.2 to 5.0]) but not congestive heart failure (odds ratio, 2.1 [CI, 0.7 to 6.0]) and ventricular tachycardia [corrected] (odds ratio, 1.8 [CI, 0.7 to 4.7]). Wall motion score was a univariate predictor of all cardiac outcomes (odds ratio for each 3-unit increase, 1.6 [CI, 1.3 to 2.1]) and ventricular tachycardia (odds ratio, 1.6 [CI, 1.2 to 2.2]) but was only a multivariable risk factor for all events (odds ratio, 1.3 [CI, 1.0 to 1.7]). An ejection fraction less than 40% had a sensitivity of 0.28 to 0.31 and a specificity of 0.87 to 0.89 for all categories of adverse outcomes. Likelihood ratios for ejection fraction had poor operating characteristics. Adding echocardiographic information to predictive models that contained known clinical risk factors did not alter sensitivity, specificity, or predictive values in clincally important ways. CONCLUSIONS: The data did not support the use of transthoracic echocardiography for the assessment of cardiac risk before noncardiac surgery. Echocardiographic measurements had limited prognostic value and suboptimal operating characteristics.

Transthoracic and transesophageal echocardiography pre and post percutaneous mitral catheter balloon valvulotomy.

Catheter balloon valvulotomy (CBV) is useful in the relief of rheumatic mitral stenosis. Morphologic scoring of the mitral valve by transthoracic echocardiography is predictive of success with CBV. Horizontal plane transesophageal echocardiography can obtain high quality images of the mitral valve and left atrium, but its value with routine use in the pre and post CBV setting is unknown. We prospectively examined 14 patients with mitral stenosis, pre and post CBV, noting scores, complications of mitral stenosis, and complications of CBV. Mitral valve scoring was similar by TTE and TEE pre and post CBV, but TEE did tend to underestimate scores pre CBV. There was a single thrombus, it was detected only by TEE. Post CBV, both TTE and TEE detected one of two torn chordae. Of three patients with ASD's by colour flow mapping, TTE and TEE each detected two. Increases in mitral insufficiency post CBV were seen equally frequently by TTE and TEE. The increases appeared to be of a higher grade (NS) by TEE. TTE and TEE yielded complementary findings, pre and post CBV. Other than for the detection of thrombi through, the net clinical contribution of routine use of TEE appears small, and large series would be needed to establish its contribution.

Scintigraphic and electrocardiographic evidence of silent coronary artery disease in asymptomatic hypertension: a case-control study.

OBJECTIVES: This study was conducted to determine the incidence of physiologically significant coronary artery disease in a group of asymptomatic high risk men with essential hypertension and to assess the validity of noninvasive tests in a subset of these patients undergoing coronary arteriography. METHODS: Two hundred twenty-six asymptomatic men (mean age 61 +/- 8 years) with essential hypertension and no clinical evidence of coronary artery disease but with at least one additional coronary risk factor were studied prospectively. Fifty age- and risk factor-matched normotensive subjects were evaluated as a control group. After a minimum of 4 days without medication, subjects underwent stress thallium-201 scintigraphy, exercise and 48-h ambulatory electrocardiography, and echocardiography. Coronary angiography was performed in a subset of 34 (40%) of 84 patients with one or more positive test results. RESULTS: A positive thallium-201 scintigram (18% vs. 6%; odds ratio 3.4, confidence interval 0.95 to 10.8, p = 0.056), exercise electrocardiograms (ECGs) (37% vs. 13%; odds ratio 4.1, confidence interval 1.5 to 11.2, p < 0.003) and ambulatory ECG (15% vs. 0%, p < 0.05) were more common in the hypertensive group than in the control group. In the cohort undergoing coronary angiography, thallium-201 scintigraphy was both sensitive and specific for epicardial atherosclerotic coronary disease (90% and 79%, respectively), but positive exercise and ambulatory ECGs occurred frequently in the absence of significant coronary stenoses. In the 39% of hypertensive patients who had mild to moderate left ventricular hypertrophy, positive exercise and ambulatory ECGs occurred at a higher rate. CONCLUSIONS: These findings suggest that physiologically significant coronary artery disease occurs more frequently in asymptomatic hypertensive men than in comparable normotensive control subjects. In the subgroup undergoing coronary arteriography, reversible scintigraphic defects were both sensitive and specific for diagnosing epicardial coronary artery disease, but exercise and ambulatory ECGs appeared to yield frequent false positive results, especially when left ventricular hypertrophy was present. These results indicate that patients with "silent" coronary artery disease can be identified among high risk hypertensive patients, but the appropriate application of such screening in clinical practice remains to be determined.

Monitoring for myocardial ischemia during noncardiac surgery. A technology assessment of transesophageal echocardiography and 12-lead electrocardiography. The Study of Perioperative Ischemia Research Group.

OBJECTIVE: Transesophageal echocardiography (TEE) and 12-lead electrocardiography (ECG) are sophisticated techniques that are increasingly being used to monitor for myocardial ischemia during noncardiac surgery. We examined whether the routine use of these techniques has incremental clinical value in identifying patients at high risk for perioperative ischemic outcomes when compared with preoperative clinical data and intraoperative monitoring using continuous two-lead bipolar ECG. DESIGN: Cohort study. SETTING: Veterans Affairs medical center. PATIENTS: A total of 332 men undergoing noncardiac surgery who had or were at high risk for coronary artery disease. INTERVENTIONS: TEE, 12-lead ECG, and two-lead ECG were performed continuously during noncardiac surgery (47% vascular, 53% nonvascular). Monitoring results were not available to anesthesiologists or surgeons, and data were blindly analyzed after surgery. MAIN OUTCOME MEASURE: Perioperative ischemic outcomes (cardiac death, nonfatal myocardial infarction, unstable angina). RESULTS: In a subset of 285 patients who were adequately studied by all three techniques, 111 patients (39%) were identified as having intraoperative myocardial ischemia (by one or more monitoring techniques). By univariate analysis, intraoperative ischemia was associated with all perioperative cardiac outcomes, including ischemic outcomes, congestive heart failure, and ventricular tachycardia (P less than or equal to .02 for each of the three monitoring techniques). However, when monitoring results for TEE and 12-lead ECG were added to a multivariate model that included preoperative clinical data and continuous two-lead ECG results, the incremental value of TEE was small (odds ratio, 2.6; 95% confidence interval [CI], 1.2 to 5.7; P = .02) and that of 12-lead ECG was not significant (odds ratio, 1.5; 95% CI, 0.6 to 3.8). Furthermore, when the multivariate analysis was repeated with only ischemic outcomes, neither TEE nor 12-lead ECG retained significant associations (odds ratio, 2.2; 95% CI, 0.5 to 9.4, and odds ratio, 1.1; 95% CI, 0.2 to 6.1, respectively). CONCLUSION: When compared with preoperative clinical data and intraoperative monitoring using two-lead ECG, routine monitoring for myocardial ischemia with TEE or 12-lead ECG during noncardiac surgery has little incremental clinical value in identifying patients at high risk for perioperative ischemic outcomes.

Diagnostic accuracy of exercise thallium-201 scintigraphy in men with asymptomatic essential hypertension.

Coronary artery disease is responsible for much of the morbidity and mortality in patients with essential hypertension, and these complications have proven to be relatively resistant to antihypertensive therapy. However, the diagnosis of coronary disease in the hypertensive population has been considered problematic. In the present study, 30 asymptomatic patients with mild to moderate hypertension with positive exercise electrocardiograms (ECG) or stress thallium-201 scintigrams underwent coronary angiography to determine the accuracy of these tests for coronary artery disease. The exercise ECG was positive in 25 subjects, of whom 15 had significant coronary lesions and 10 did not. Thallium-201 scintigraphy proved more accurate: 17 of 18 patients with reversible abnormalities had significant obstructive coronary disease anatomically corresponding to the defect, one patient with a fixed defect had normal coronary arteries and was found to have an idiopathic cardiomyopathy, and 9 of 11 without defects had no significant lesions. The results were similar in populations with and without echocardiographic criteria for left ventricular hypertrophy. These findings indicate that despite previous suggestions to the contrary, thallium-201 scintigraphy can accurately diagnose coronary artery disease in most patients with asymptomatic essential hypertension, and that most asymptomatic hypertensive patients with physiologic evidence of myocardial ischemia have associated coronary artery disease.

Predictors of postoperative myocardial ischemia in patients undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group.

OBJECTIVE: To identify predictors of postoperative myocardial ischemia in patients scheduled to undergo major noncardiac surgery. DESIGN: Historical, clinical, laboratory, and physiological data were obtained prospectively before and during surgery to identify potential univariate predictors of postoperative myocardial ischemia, which then were entered into multivariate logistic models. Continuous two-lead electrocardiograms before, during, and after surgery were used to identify episodes of myocardial ischemia. SETTING: Department of Veterans Affairs tertiary care hospital. PATIENTS: A consecutive sample of 474 men at high risk for or with coronary artery disease who were scheduled to undergo major noncardiac surgery (95% compliance rate). MAIN OUTCOME MEASURE: Significant variables identified by multivariate logistic models that are associated with postoperative myocardial ischemia. RESULTS: Five major preoperative predictors of postoperative myocardial ischemia were identified: (1) left ventricular hypertrophy by electrocardiogram; (2) history of hypertension; (3) diabetes mellitus; (4) definite coronary artery disease; and (5) use of digoxin. The risk of postoperative myocardial ischemia increased progressively with the number of predictors present: in 22% of patients with no predictors, in 31% with one predictor, in 46% with two predictors, in 70% with three predictors, and in 77% with four predictors. CONCLUSION: Patients subgroups who are at high risk for developing postoperative myocardial ischemia and who might benefit the most from intensive Holter monitoring in the postoperative period now can be identified preoperatively.

Hibernating myocardium: a historical perspective.

Hibernating myocardium refers to the presence of persistent myocardial and left ventricular dysfunction at rest, associated with conditions of severely reduced coronary blood flow. This left ventricular dysfunction probably represents an adaptive mechanism preventing irreversible myocardial cell damage, since myocardial and left ventricular dysfunction in hibernating myocardium improve following the restoration of coronary blood flow. This review examines the evolution of the concept of hibernation from a clinical observation of the potential underlying mechanisms recently proposed.

What is the role of silent coronary artery disease and left ventricular hypertrophy in the genesis of ventricular arrhythmias in men with essential hypertension?

Ventricular arrhythmias are not uncommon in patients with hypertension, are often attributed to left ventricular hypertrophy and are thought to be associated with an increased risk of sudden death. However, underlying silent coronary artery disease, another potential cause of ventricular arrhythmias, is often present in the same patient group. Therefore, the prevalence of ventricular arrhythmias was prospectively examined in 183 consecutive asymptomatic men with hypertension with neither clinical nor electrocardiographic (ECG) evidence of coronary artery disease in whom technically adequate echocardiograms could be obtained. After previous therapy had been withdrawn for greater than or equal to 4 days, each patient underwent exercise or dipyridamole thallium-201 scintigraphy, 48-h Holter ambulatory ECG monitoring and echocardiography for measurement of the left ventricular mass index. Forty patients (22%) had frequent ventricular ectopic activity, defined on the basis of greater than 10 premature ventricular complexes/h (38 patients) or ventricular tachycardia (11 patients), or both. A higher proportion of patients with than without a reversible thallium-201 defect had frequent premature ventricular complexes (33% vs. 18%, p less than 0.02) or ventricular tachycardia (14% vs. 4%, p less than 0.02). Similarly, more patients with than without left ventricular hypertrophy (defined as left ventricular mass index greater than or equal to 134 g/m2) had frequent premature ventricular complexes (29% vs. 15%, p less than 0.05) and ventricular tachycardia (12% vs. 2%, p less than 0.01). By stepwise logistic regression analysis, both findings were independent predictors of ventricular arrhythmia, which was present in 53% of patients with both abnormalities, but in only 12% of those with neither abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of left ventricular contractility using transesophageal echocardiography in patients undergoing coronary artery bypass grafting. The Study of Perioperative Ischemia (SPI) Research Group.

Optimal assessment of left ventricular function requires the use of load-independent indices of myocardial contractility, which often are difficult to obtain in patients undergoing coronary artery bypass graft (CABG) surgery. We have investigated whether the relation between left ventricular end-systolic stress (ESS) (derived from high-fidelity intraventricular pressure measurements and transesophageal-derived wall thickness) and end-systolic area (ESA) (derived from transesophageal echocardiography [TEE]) could provide a load-independent index of left ventricular function. We studied seven men undergoing coronary revascularization. Multiple data points at varied loading conditions were generated for each patient by infusions of sodium nitroprusside and phenylephrine during the period immediately after induction of general anesthesia and preceding surgical incision. While peak systolic blood pressure was pharmacologically altered between 78 and 204 mm Hg, the correlations between ESS and ESA were excellent for all patients (range r = 0.90 to 0.99). Additionally, the slopes of these relations showed a close correlation to their respective baseline thermodilution cardiac indices (r = 0.85, p = 0.02). Appropriate shifts of the ESS/ESA relationships were documented during postextrasystolic potentiation. The authors conclude that the left ventricular ESS/ESA correlation, derived using TEE and intraventricular pressure measurements, may provide a load-independent index of left ventricular inotropic state in patients undergoing CABG surgery.

Dipyridamole thallium-201 scintigraphy as a preoperative screening test. A reexamination of its predictive potential. Study of Perioperative Ischemia Research Group.

BACKGROUND: We examined the value of dipyridamole thallium-201 (201Tl) scintigraphy as a preoperative screening test for perioperative myocardial ischemia and infarction. METHODS AND RESULTS: We prospectively studied 60 patients undergoing elective vascular surgery. We performed 201Tl scintigraphy preoperatively and blinded all treating physicians to the results. Historical, clinical, laboratory, and physiological data were gathered throughout hospitalization. Myocardial ischemia was assessed during the intraoperative period using continuous 12-lead electrocardiography (ECG) and transesophageal echocardiography (TEE) and during the postoperative period using continuous two-lead ambulatory ECG. Adverse cardiac outcomes (cardiac death, myocardial infarction, unstable angina, severe ischemia, or congestive heart failure) were assessed daily throughout hospitalization. Twenty-two patients (37%) had defects that improved or reversed on delayed scintigrams (redistribution defects), 18 (30%) had persistent defects, and 20 (33%) had no defects on 201Tl scintigraphy. There was no association between redistribution defects and adverse cardiac outcomes: 54% (seven of 13) of adverse outcomes occurred in patients without redistribution defects, and the risk of an adverse outcome was not significantly increased in patients with redistribution defects (relative risk 1.5, 95% confidence interval 0.6-3.9, p = 0.43). Consistent with these findings, there was also no association between redistribution defects and perioperative ischemia: 54% (19 of all 35) of perioperative ECG and TEE ischemic episodes and 58% (14 of 24) of severe ischemic episodes occurred in patients without redistribution defects. The sensitivity of 201Tl scintigraphy for perioperative ischemia and adverse outcomes ranged from 40% to 54%, specificity from 65% to 71%, positive predictive value from 27% to 47% and negative predictive value from 61% to 82%. CONCLUSIONS: These results differ from those of previous studies and suggest that the routine use of 201Tl scintigraphy for preoperative screening of patients undergoing vascular surgery may not be warranted.

Perioperative myocardial ischemia in patients undergoing noncardiac surgery--I: Incidence and severity during the 4 day perioperative period. The Study of Perioperative Ischemia (SPI) Research Group.

To determine the incidence and characteristics of perioperative myocardial ischemia, the electrocardiographic (ECG) changes consistent with ischemia during the 4 day perioperative period were documented and characterized in 100 patients with or at risk for coronary artery disease undergoing noncardiac surgery. Using continuous two channel ECG monitoring (leads CC5 and CM5), the frequency and severity of ECG ischemic episodes defined by ST segment depression greater than or equal to 1 mm or elevation greater than or equal to 2 mm during the preoperative (up to 2 days), intraoperative and early postoperative (first 2 days) periods were compared. Preoperatively, 28 patients (28%) exhibited 105 episodes of ischemia; intraoperatively, 27 patients exhibited 39 episodes and postoperatively, 42 patients exhibited 187 episodes. There was no difference between the pre- and intraoperative episode characteristics. However, postoperative ischemic episodes were the most severe. The mean ST change was 1.5, 2 and 2.6 mm for pre-, intra- and postoperative episodes, respectively (p less than 0.0001 postoperative versus pre- or intraoperative); duration of ischemic episodes was 69, 45 and 207 min, respectively (p less than 0.005 postoperative versus preoperative, p less than 0.001 versus intraoperative) and area under the ST curve was 88, 74 and 383 mm.min (p less than 0.009 postoperative versus preoperative, p less than 0.005 versus intraoperative). Ninety-four percent of all postoperative ischemic episodes were silent; 80% of all episodes occurred without acute change (+/- 20% of control) in heart rate and 77% of intraoperative episodes occurred without acute change in blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative myocardial ischemia in patients undergoing noncardiac surgery--II: Incidence and severity during the 1st week after surgery. The Study of Perioperative Ischemia (SPI) Research Group.

Because of the importance of postoperative myocardial ischemia and because substantial physiologic changes can occur for prolonged periods postoperatively, the incidence, severity and temporal course of myocardial ischemia were studied in 100 high risk patients during the 1st week after major noncardiac surgery. Electrocardiographic (ECG) changes consistent with ischemia were continuously monitored using ambulatory solid state ECG in the 100 patients with or at risk for coronary artery disease. Ischemic episodes were defined as reversible ST segment depression greater than or equal to 1 mm or elevation greater than or equal to 2 mm above the baseline value, with the baseline adjusted for respiratory and positional variation and temporal drift. All ischemic episodes were confirmed by three independent blinded investigators using hard-copy recordings. Total ECG monitoring time was 10,445 h. Twenty-seven patients (27%) developed 437 episodes of ischemia during the 1st week after surgery. The total duration of ischemia was 18,658 min, or 1.8 min of ischemia/h monitored. Ischemia was most severe during the early (days 0 to 3) versus late (days 4 to 7) postoperative period: 284 versus 153 episodes; 2.2 versus 1.2 min of ischemia/h. The greatest severity occurred on postoperative day 3: 109 episodes, 3.4 min of ischemia/h monitored, 1.5 mm mean ST change and 130 min mean duration. However, in 8% of patients, severe episodes also occurred late: postoperative day 6 = 44 episodes, 1.7 min of ischemia/h monitored, 1.3 mm mean ST change (59% greater than or equal to 2 mm) and 92 min mean duration. Most ischemic episodes (57%) were associated with tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of therapy on silent ischemia and ventricular arrhythmias in hypertensive patients.

To assess whether therapy with hydrochlorothiazide (HCTZ) or the calcium antagonist nitrendipine influences silent ischemia or arrhythmias, we studied 10 asymptomatic hypertensive male patients with positive Tl-201 scintigraphy in a double-blind, crossover protocol. Blood pressure (BP) and 48-h Holter monitoring were obtained after 2 weeks of placebo and 8 weeks each of HCTZ and nitrendipine therapy. Ischemia was defined as greater than 1 mm ST-segment depression lasting greater than 1 min and was quantified by the number of episodes, duration, and area under the curve (AUC). The mean number of PVCs per hour and the number of episodes of ventricular tachycardia (greater than 3 beats) were also assessed. Diastolic BP was significantly reduced by both HCTZ and nitrendipine (98 +/- 6 vs. 90 +/- 6 vs. 88 +/- 7 mm Hg, respectively, p less than 0.05), but systolic BP was unchanged for either drug. The number of ischemic episodes was reduced by nitrendipine, from 2.4 +/- 3 to 0.8 +/- 2, (p less than 0.05) but not by HCTZ (2.4 +/- 3 to 1.5 +/- 3, p = NS). The duration of ischemia (37 +/- 43 vs. 5 +/- 9 min, p less than 0.05) as well as the AUC (41 +/- 45 vs. 7 +/- 14 mm/min, p less than 0.05) were reduced only by nitrendipine. The number of PVCs rose with HCTZ therapy, from 19 +/- 34 to 69 +/- 88 (p less than 0.05) and was unchanged by nitrendipine (19 +/- 34 vs. 19 +/- 40, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Association of perioperative myocardial ischemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group.

BACKGROUND: Adverse cardiac events are a major cause of morbidity and mortality after noncardiac surgery. It is necessary to determine the predictors of these outcomes in order to focus efforts on prevention and treatment. Patients undergoing noncardiac surgery sometimes have postoperative cardiac events. It would be helpful to know which patients are at highest risk. METHODS: We prospectively studied 474 men with coronary artery disease (243) or at high risk for it (231) who were undergoing elective noncardiac surgery. We gathered historical, clinical, laboratory, and physiologic data during hospitalization and for 6 to 24 months after surgery. Myocardial ischemia was assessed by continuous electrocardiographic monitoring, beginning two days before surgery and continuing for two days after. RESULTS: Eighty-three patients (18 percent) had postoperative cardiac events in the hospital that were classified as ischemic events (cardiac death, myocardial infarction, or unstable angina) (15 patients), congestive heart failure (30), or ventricular tachycardia (38). Postoperative myocardial ischemia occurred in 41 percent of the monitored patients and was associated with a 2.8-fold increase in the odds of all adverse cardiac outcomes (95 percent confidence interval, 1.6 to 4.9; P less than 0.0002) and a 9.2-fold increase in the odds of an ischemic event (95 percent confidence interval, 2.0 to 42.0; P less than 0.004). Multivariate analysis showed no other clinical, historical, or perioperative variable to be independently associated with ischemic events, including cardiac-risk index, a history of previous myocardial infarction or congestive heart failure, or the occurrence of ischemia before or during surgery. CONCLUSIONS: In high-risk patients undergoing noncardiac surgery, early postoperative myocardial ischemia is an important correlate of adverse cardiac outcomes.

The "natural history" of segmental wall motion abnormalities in patients undergoing noncardiac surgery. S.P.I. Research Group.

Intraoperative segmental wall motion abnormalities (SWMA) detected by transesophageal echocardiography (TEE) are sensitive, but not always specific, markers of myocardial ischemia. To determine their incidence, characteristics, and relation to postoperative cardiac morbidity, we continuously recorded the left ventricular short-axis view and 12-lead ECG in 156 high-risk patients undergoing non-cardiac surgery. Monitoring was clinically blinded. Wall motion was scored at predefined clinical, hemodynamic, and ECG events and at periodic intervals (26 +/- 11 samples per patient). We detected 44 episodes of new or worsened SWMA in 32 patients (20%). The severity of most episodes was limited to severe hypokinesis (24/44, 55%) followed by akinesis (16/44, 36%) and dyskinesis (4/44, 9%). The remaining 124 patients had normal wall motion or only mild hypokinesis (56/156, 36%) or chronic SWMA (68/156, 44%). The incidence of new SWMA did not differ for patients with known coronary artery disease (CAD) and those with cardiac risk factors only (22% vs. 19%, P = not significant), although CAD patients had a significantly greater incidence of chronic SWMA (62% vs. 41%, P = 0.02). The incidence of new or worsened SWMA was significantly greater during aortic vascular surgery (38% vs. 17%, P = 0.05). Approximately 40% of all new TEE changes occurred in the absence of either an apparent clinical event or a significant change in systolic blood pressure or heart rate. Ten patients had new or worsened SWMA persisting until the end of surgery, 8 with new akinesis, only 1 developing myocardial infarction. The distribution of new or worsened SWMA and significant intraoperative ST-T changes (n = 19) in this cohort was discordant: temporal overlap between modalities was present in only 5 patients. Major cardiac complications occurred in 5 patients (3.2%), all of whom underwent peripheral vascularization. All patients with cardiac complications and new or worsened SWMA also had intraoperative or early postoperative ST-T changes. We conclude that: 1) continuous TEE recording with offline analysis in this high-risk group of patients revealed a relatively low incidence of new or worsened SWMA (20%), most episodes of which were characterized by severe hypokinesis (55%); 2) episodes were more common in patients undergoing aortic vascular surgery; 3) approximately 40% of episodes were unaccompanied by clinical events or significant hemodynamic changes; 4) episodes were poorly correlated with postoperative cardiac complications; and 5) the discordant relation between TEE and ECG changes observed here necessitates careful monitoring of the ECG when TEE is used clinically.

Correlates of diastolic filling abnormalities in hypertension: a Doppler echocardiographic study.

Hypertension and aging are both associated with changes of left ventricular (LV) diastolic filling and increased LV mass. To determine whether diastolic filling abnormalities are present in hypertension independent of aging and significant hypertrophy, we studied 19 hypertensive patients following a period of 4 weeks when they were not receiving therapy and 18 normotensive subjects matched for sex, age, and LV mass. All subjects had normal systolic function and ejection fraction as assessed by radionuclide angiography. We measured peak velocity of early filling (E), late filling (A), and their ratio (E/A) by Doppler echocardiography. Filling indices were abnormal in hypertensive patients, but none of the filling indices were significantly correlated with LV mass. E was inversely related to age (r = -0.62; p less than 0.01) and diastolic blood pressure (r = 0.45; p less than 0.05) in normotensive individuals, but these correlations were not significant in hypertensive patients. E was not significantly correlated to LV mass or wall thickness. In contrast, A was influenced by septal wall thickness and blood pressure in both groups. E/A correlated inversely with age in both normal individuals (r = -0.74) and hypertensive patients (r = -0.51). These findings indicate that diastolic filling abnormalities in hypertension are not solely caused by either LV hypertrophy or by aging and therefore must be in part related to the hemodynamic load or altered myocardial or chamber properties.

Left ventricular hypertrophy reversal with labetalol and propranolol: a prospective randomized, double-blind study.

Hypertensive patients with left ventricular hypertrophy (LVH) have increased cardiovascular morbidity and mortality. Experimental studies indicate the importance of both the alpha and beta components of the adrenergic nervous system in the development and reversal of LVH. Therefore labetalol (L), a combined alpha and beta blocker, and propranolol (P), a nonselective beta blocker, were evaluated in a randomized, double-blind study of 35 hypertensive patients with echocardiographic evidence of LVH. Following 2 weeks of placebo, L or P was titrated as needed and tolerated to maximum total daily doses of 1600 mg and 640 mg, respectively. A thiazide diuretic was added if necessary for blood pressure control. M-mode echocardiograms were performed at baseline and after 1, 3, 6, and 12 months of blood pressure control. The echocardiograms were read independently by two blinded observers for end-diastolic dimension and wall thicknesses, and left ventricular mass. Fractional shortening, cardiac output, and peripheral vascular resistance were derived using standard formulas. Both drugs reduced blood pressure significantly and comparably. Significant changes in the echocardiographic measurements were observed as early as 1 month and usually persisted throughout the study. Both drugs decreased posterior wall thickness; however, only the decrease in propranolol group achieved statistical significance. Septal wall thickness was reduced by L at 3 and 12 months. End-diastolic dimension increased significantly in the L-treated group at 3, 6, and 12 months of therapy, whereas P had no effect on this measurement.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired left ventricular functional reserve in hypertensive patients with left ventricular hypertrophy.

To determine whether patients with hypertension and especially those with left ventricular hypertrophy have subtle changes in cardiac function, we measured the increase in left ventricular ejection fraction and in systolic blood pressure to end-systolic volume index ratio with exercise in 40 hypertensive patients and 16 age-matched normotensive volunteers. Twenty-two hypertensive patients without hypertrophy had normal end-systolic wall stress at rest and exercise responses. In contrast, the 18 patients with echocardiographic criteria for left ventricular hypertrophy demonstrated a significant increase in end-systolic wall stress at rest compared with normal subjects (69 +/- 16 vs. 55 +/- 15 10(3) x dyne/cm2, p less than 0.05) despite having normal resting left ventricular size and ejection fraction. In patients with left ventricular hypertrophy, the increase in ejection fraction with exercise was less than in the normotensive control subjects (7 +/- 7 vs. 12 +/- 8 units, p less than 0.05), and delta systolic blood pressure to end-systolic volume with exercise was reduced (3.3 +/- 3.8 vs. 8.3 +/- 7.7 mm Hg/ml/m2, p less than 0.05). The hypertensive patients with hypertrophy displayed a shift downward and to the right in the relation between systolic blood pressure to end-systolic volume ratio and end-systolic wall stress compared with control subjects and hypertensive patients without left ventricular hypertrophy. Thus, hypertensive patients with left ventricular hypertrophy by echocardiography and normal resting ejection fraction exhibit abnormal ventricular functional responses to exercise. This finding may have implications in identifying patients at higher risk for developing heart failure.