Geometric and functional correlates of electrocardiographic repolarization and voltage abnormalities in aortic regurgitation.

Although electrocardiographic left ventricular hypertrophy is a recognized marker of disease severity in patients with chronic aortic regurgitation, the quantitative relations of repolarization abnormalities and QRS voltage to measurements of cardiac structure and function have not been established. The presence or absence of the "strain" pattern of repolarization and QRS voltage was compared with echocardiographic and radionuclide cineangiographic findings in 95 adults with sever, pure, chronic aortic regurgitation and no evidence of coronary artery disease. In contrast to 54 patients with normal repolarization, 41 patients with an abnormal repolarization pattern had greater left ventricular end-diastolic and end-systolic dimensions (7.2 +/- 1.1 versus 6.6 +/- 0.8 cm, p less than 0.002 and 5.2 +/- 1.2 versus 4.4 +/- 0.7, p less than 0.001, respectively), greater left ventricular mass (431 +/- 138 versus 303 +/- 89 g, p less than 0.001), higher end-systolic stress (128 +/- 46 versus 95 +/- 27 dynes-cm2 X 10(3), p less than 0.001), lower fractional shortening (28 +/- 8 versus 34 +/- 5%, p less than 0.001) and lower exercise ejection fraction (39 +/- 11 versus 51 +/- 8%, p less than 0.001). Multiple logistic regression analysis revealed that left ventricular mass and end-systolic stress were independently related to the presence of repolarization abnormalities (p less than 0.005). Among the 73 asymptomatic patients, those with normal repolarization had significantly lower prevalences of fractional shortening less than 25% (1 of 45 versus 5 of 27, p less than 0.05), left ventricular systolic dimension greater than 5.5 cm (1 of 45 versus 8 of 27, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous coronary revascularization: results of a large regional prospective study. Northern New England Cardiovascular Disease Study Group.

OBJECTIVES: We sought to assess survival among patients with diabetes and multivessel coronary artery disease (MVD) after percutaneous coronary intervention (PCI) and after coronary artery bypass grafting surgery (CABG). BACKGROUND: The Bypass Angioplasty Revascularization Investigation (BARI) demonstrated that diabetics with MVD survive longer after initial CABG than after initial PCI. Other randomized trials or observational databases have not conclusively reproduced this result. METHODS: A large, regional database was linked to the National Death Index to assess five-year mortality. Of 7,159 consecutive patients with diabetes who underwent coronary revascularization in northern New England during 1992 to 1996, 2,766 (38.6%) were similar to those randomized in the BARI trial. Percutaneous coronary intervention was the initial revascularization strategy in 736 patients and CABG in 2,030. Cox proportional hazards regression was used to calculate risk-adjusted hazard ratios (HR) and 95% confidence intervals (CI 95%). RESULTS: Patients who underwent PCI were younger, had higher ejection fractions and less extensive coronary disease. After adjusting for differences in baseline clinical characteristics, patients with diabetes treated with PCI had significantly greater mortality relative to those undergoing CABG (HR = 1.49; CI 95%: 1.02 to 2.17; p = 0.037). Mortality risk tended to increase more among 1,251 patients with 3VD (HR = 2.02; CI 95%: 1.04 to 3.91; p = 0.038) than among 1,515 patients with 2VD (HR = 1.33; CI 95%: 0.84 to 2.1; p = 0.21). CONCLUSIONS: In this analysis of a large regional contemporary database of patients with diabetes selected to be similar to those enrolled in the BARI trial, five-year mortality was significantly increased after initial PCI. This supports the BARI conclusion on initial revascularization of patients with diabetes and MVD.

Comparison of mitral valve dimensions and motion in mitral valve prolapse with severe mitral regurgitation to uncomplicated mitral valve prolapse and to mitral regurgitation without mitral valve prolapse.

To determine the mitral valve abnormalities associated with hemodynamically important mitral regurgitation (MR) among patients with mitral valve prolapse (MVP), computerized 2-dimensional echocardiographic measurements of mitral leaflet and anular dimensions and motion in 26 patients with MVP and MR were compared to those in 48 subjects with uncomplicated MVP, 16 patients with MR due to etiologies other than MVP (rheumatic in 8) and 35 normal adults. Compared to both uncomplicated MVP and normal subjects, patients with MVP plus MR were older (p less than 0.05), had strikingly large mitral leaflets and anulus (p less than 0.0005) and were more likely to have systolic billowing of mitral leaflets in the parasternal long-axis view (24 of 26 [92%] vs 24 of 48 subjects with uncomplicated MVP [50%], p less than 0.001). Overlap in anular and posterior leaflet dimensions in normal and uncomplicated MVP subjects occurred in the 20 MVP plus MR patients who continue to be followed medically but not in the 6 MVP plus MR patients who underwent mitral valve surgery during 22 +/- 14 months follow-up. Patients with MR due to rheumatic or other non-MVP etiologies had enlargement of mitral leaflets and anulus virtually identical to that in MVP plus MR patients. In conclusion, patients with severe MR due to MVP are older, have striking mitral valve enlargement and more frequently exhibit leaflet billowing compared with subjects with uncomplicated MVP. Similar mitral leaflet enlargement was found in patients with non-MVP etiologies of MR, suggesting that mitral anular and leaflet enlargement may play a more general role in the pathogenesis of MR than is currently appreciated.

Return to work after coronary artery bypass operation.

A societal cost-benefit argument has been made for the coronary artery bypass graft (CABG) operation. Most patients experience improvement in symptoms and many can return to a productive livelihood. To estimate the rate of return to work and identify the factors influencing that outcome, we analyzed the work status before and after operation in a follow-up of 105 patients undergoing CABG operations in a new teaching hospital. Overall, relief or improvement in angina was accomplished in 92% of patients, and there was a 10% net increase to th work force after operation. Of all variables studied, preoperative work status was found to be the most statistically significant predictor of the postoperative return to work; other factors associated with return to work included symptomatic relief or improvement, age, and educational level. Preoperative and postoperative means of support did not play a major role in determining work outcome.

Increasing the value of cardiac care: the Dartmouth approach.

UNLABELLED: A cardiac services team at Dartmouth-Hitchcock Medical Center (DHMC) launched multiple efforts to improve the quality and value of their services. The team developed a critical path for coronary artery bypass grafting (CABG) and tracked important clinical outcomes, such as mortality rates and wound complications. The team also studied the patient's view of the process. Staff used focus groups and surveys to distill the "voice of the customer" into six quality characteristics and developed methods to better involve patients in clinical decision making and evaluation of treatment efficacy. RESULTS: CABG mortality declined from 5.7 percent in 1992 to 2.7 percent in 1994, 16 months after the critical path was developed. Mean total intubation time for patients following open-heart surgery was reduced from 22 hours to 14 hours. Median postoperative length of stay decreased from seven days to six for elective CABG patients. The number of patients discharged in five days or less increased from 20 percent to 40 percent. Readmission to the hospital following discharge remained stable, despite the shorter length of stay.

Double-lumen catheter assessment of aortic stenosis: comparison with separate catheter technique.

Hemodynamic assessment of aortic stenosis in the catheterization laboratory accurate determination of the transvalvular gradient. A commercially available double-lumen pigtail catheter can be used to obtain this gradient via a single arterial puncture. The catheter has several advantages over other methods used to measure the gradient in aortic stenosis, but it has not been critically evaluated. In order to assess the performance of this catheter compared to the traditional standard of separate catheters above and across the aortic valve, we studied 10 patients with aortic stenosis using both catheter systems. Aortic valve areas ranged from 0.34 cm2 to 1.1 cm2. Linear regression analysis confirmed excellent correlation between the two methods in measurement of the mean transvalvular gradient (r = 0.98) and calculation of the aortic valve area (r = 0.99) using the Gorlin formula. We conclude that the double-lumen pigtail catheter provides accurate data in the hemodynamic evaluation of aortic stenosis.

Relationship of the electrocardiographic response to exercise to geometric and functional findings in aortic regurgitation.

The exercise ECGs of 30 patients with pure aortic regurgitation (AR) were compared with functional and geometric variables measured by echocardiography and radionuclide cineangiography. The 10 patients with positive ECG responses to exercise (greater than or equal to 0.1 mV additional downsloping or horizontal ST segment depression) were similar to the 20 patients with negative tests with respect to mean age, exercise duration, peak work load achieved, symptoms, and resting ECG findings. Patients with positive exercise tests had significantly reduced left ventricular (LV) ejection fractions at rest (44 +/- 4% vs 52 +/- 2%) and during peak exercise (38 +/- 3% vs 48 +/- 2%), lower fractional shortening at rest (27 +/- 1% vs 34 +/- 2%), higher end-systolic wall stress (150 +/- 18 vs 99 +/- 8 dynes/cm2 X 10(3], lower left ventricular relative wall thickness (0.26 +/- 0.01 vs 0.30 +/- 0.01), and greater end-systolic diameter (5.7 +/- 0.3 vs 4.5 +/- 0.2 cm) than patients with negative tests (p less than 0.05 for all comparisons). Among the 18 asymptomatic patients, positive tests were associated with lower resting fractional shortening, lower exercise ejection fraction, higher wall stress, and greater end-systolic diameter. These data demonstrate that a positive exercise ECG in aortic regurgitation identifies patients, even when asymptomatic, who have developed markedly abnormal left ventricular functional and geometric responses to volume load, while a negative exercise ECG identifies a subset of asymptomatic patients who are unlikely to have severe ventricular dysfunction.

Reversal of left ventricular dilatation, hypertrophy, and dysfunction by valve replacement in aortic regurgitation.

Although aortic valve replacement for aortic regurgitation relieves left ventricular volume overload, ventricular geometry does not consistently normalize. To assess the extent, determinants, and functional consequences of reversal of left ventricular dilatation and hypertrophy, 38 patients with severe aortic regurgitation were studied pre- and postoperatively by serial echocardiography and radionuclide cineangiography. Left ventricular end-diastolic dimension normalized in 58% of patients by 9 +/- 6 months postoperatively, at which time 50% of patients had normalized mass; cumulative normalization rose to 66% for end-diastolic dimension and 68% for left ventricular mass during further follow-up. All patients who had normalized end-diastolic dimension also had normal postoperative ejection fractions (mean 61 +/- 8%). In contrast, patients in whom the left ventricle remained dilated had a 42% prevalence of subnormal postoperative left ventricular ejection fraction. Preoperative left ventricular end-systolic dimension less than or equal to 55 mm identified 86% of patients in whom end-diastolic dimension normalized, whereas end-systolic dimension exceeded 55 mm in 81% of those with persistent dilatation; other proposed preoperative predictors of operative outcome correctly identified lower proportions (from 59% to 71%) of patients in whom left ventricular size did or did not normalize. In conclusion, aortic valve replacement resulted in normalized left ventricular chamber size and mass in two thirds of the patients selected for operation by current criteria; favorable geometric outcome is associated with persistence or recovery of normal left ventricular function.

Relationship of atrial natriuretic factor to left ventricular volume and mass.

Although atrial natriuretic factor is primarily of atrial origin, recent observations indicate that the hormone is also synthesized by hypertrophied left ventricular myocardium. To assess the separate influences of left ventricular and left atrial dilatation and left ventricular hypertrophy on human atrial natriuretic factor levels, left atrial dimension and volume and left ventricular dimension and mass were compared in 49 normal subjects, in 33 patients with chronic aortic regurgitation, and in 15 patients with chronic mitral regurgitation. When compared with normal subjects, patients with chronic aortic and mitral regurgitation had similarly dilated and hypertrophied left ventricles (p less than 0.0005), while only mitral regurgitation patients had significantly enlarged (p less than 0.0005) mean left atrial dimension and volume. Likewise, plasma atrial natriuretic factor was elevated among patients with mitral regurgitation (60.3 +/- 47.0 fmol/ml) but was normal in patients with aortic regurgitation (19.0 +/- 11.0 fmol/ml versus 12.4 +/- 5.2 fmol/ml in normals; both p less than 0.0005 versus mitral regurgitation). Among all 97 subjects, atrial natriuretic factor levels correlated more closely with left atrial dimension and volume (r = 0.62 and 0.64, p less than 0.0005) than with left ventricular dimension (r = 0.44, p less than 0.0005) or mass (r = 0.40, p less than 0.0005). In addition, multivariate analysis indicated that left atrial volume bore a stronger independent relationship to plasma atrial natriuretic factor levels than either age or left ventricular variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic root dilatation as a cause of isolated, severe aortic regurgitation. Prevalence, clinical and echocardiographic patterns, and relation to left ventricular hypertrophy and function.

To evaluate the relation of aortic root dilatation to aortic regurgitation, we examined clinical, echocardiographic, and radionuclide cineangiographic findings in 102 patients with severe aortic regurgitation. Aortic root dilatation was the only apparent cause in 31 patients (30%), exceeding in prevalence any valvular cause, and was independently associated only with older age (p less than 0.001). Echocardiography showed dilatation to be either localized to the sinuses of Valsalva or to be generalized. At initial evaluation, patients with generalized dilatation had severer abnormalities of left ventricular size and function than those with localized or no dilatation. Aortic valves were subsequently replaced in more patients with generalized than localized dilatation during 28 +/- 17 month follow-up (9 of 15 patients compared with 2 of 15, p less than 0.03). Thus, idiopathic aortic root dilatation is the commonest definable cause of severe aortic regurgitation; aortic root dilatation is associated independently with age but not blood pressure; and generalized aortic root dilatation is associated with marked ventricular dilatation, hypertrophy, and dysfunction.