Biomedical subjects
Publications and source records attributed to C Hochreiter.
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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.
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)
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.
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To determine factors influencing the strength of association between mitral valve prolapse and mitral regurgitation, ruptured chordae tendineae, and infective endocarditis, the prevalence of mitral prolapse in patients with disease was compared with both clinical and population control groups. The prevalence of mitral valve prolapse was 4 percent among population and clinical control groups (eight of 196 and 84 of 2,146, respectively) and was significantly higher (p less than 0.001) in patients with endocarditis (11 of 67, 16 percent), mitral regurgitation (17 of 31, 55 percent, and ruptured chordae (27 of 43, 63 percent). Odds ratios for complications in persons with mitral valve prolapse ranged from 4.6 for endocarditis to 41.4 for ruptured chordae in overall analyses, and from 6.8 for endocarditis to 53.0 for ruptured chordae based on age- and sex-matched case-control triplets (p less than 0.001 for each). All complications occurred disproportionately in men with mitral valve prolapse, in whom odds ratios ranged from 2.5 to 7.4 compared with an additional control group of unselected subjects with mitral valve prolapse. Compared with this control group, patients with mitral valve prolapse and endocarditis were slightly more likely to have a previously known heart murmur (odds ratio 3.2, difference not significant) but significantly more likely to have murmurs at the time of evaluation (odds ratio 8.5, p less than 0.01). Patients with mitral valve prolapse and mitral regurgitation and ruptured chordae tendineae were also significantly older than the unselected subjects with mitral valve prolapse (48 +/- 14 and 55 +/- 16 versus 38 +/- 14 years, p less than 0.005 for both). The concentration of risk of endocarditis in men with mitral valve prolapse and patients with antecedent murmur suggests that antibiotic prophylaxis is warranted in these groups but not in women without a murmur of mitral regurgitation.
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To determine objective predictors of survival, 53 patients with chronic, hemodynamically severe mitral regurgitation underwent rest and exercise radionuclide cineangiography, echocardiography, treadmill exercise testing, and ambulatory electrocardiographic monitoring before prospective (average 30 month) follow-up. At entry, symptom status correlated best with radionuclide-based right ventricular ejection fraction (RVEF) and left atrial size, while treadmill exercise tolerance correlated best with RVEF during exercise (r = .48, p less than .005). Correspondingly, in 23 patients who underwent cardiac catheterization, pulmonary arterial systolic and wedge pressures were significantly inversely related to RVEF. On the 24 hr ambulatory electrocardiogram, nonsustained ventricular tachycardia was present in 29% of patients, most frequently when both RVEF and left ventricular ejection fraction (LVEF) were subnormal (p = .03 vs other patients). Since entry, 35 patients have been managed without surgery for 9 to 57 months (average 28); three of these who subsequently underwent operation also are among the 21 patients who have undergone mitral valve replacement (MVR). During the average 28 months of observation under medical treatment five of 35 nonoperated patients have died; all five were among the six nonoperated patients with RVEFs of 30% or less at entry, a descriptor that significantly identified those at high mortality risk (p less than .0001 vs patients with RVEFs greater than 30%). All five also were among the eight nonoperated patients with LVEFs of 45% or less (lower limit of normal), a descriptor that also significantly predicted mortality. Three of the 21 patients who underwent surgery have died, all late after MVR. Among operated patients, only age was a predictor of postoperative survival. A trend toward improved survival was found in the patients with depressed right or left ventricular ejection fraction who underwent surgery compared with those who did not.
Atrial and ventricular arrhythmias were characterized by ambulatory electrocardiography in 31 patients with nonischemic mitral regurgitation (MR), 17 of whom had echocardiographic evidence of mitral valve prolapse (MVP) and 14 of whom had other causes of MR. Frequent and complex arrhythmias were common and equally prevalent in each MR subgroup, whether or not MVP was present. Multiform ventricular ectopy was found in 77% (24 of 31), ventricular couplets in 61% (19 of 31), and ventricular salvos or ventricular tachycardia in 35% (11 of 31) of patients with MR. Arrhythmias in patients with MR were significantly more prevalent than in 63 patients with MVP who had no evidence of MR. Among patients with MVP, excess arrhythmias associated with MR were most striking with respect to frequent ventricular premature complexes (41% with MR vs 3% without MR), multiform ventricular ectopic activity (88% vs 43%), ventricular couplets (65% vs 6%), and ventricular salvos or ventricular tachycardia (35% vs 5%) (p less than 0.005 for each comparison). These data demonstrate that complex arrhythmias are common in patients with nonischemic MR irrespective of etiology, and that these arrhythmias are more strongly associated with hemodynamically important MR than with MVP alone.
To assess the value and predictive limitations of the exercise ST/HR slope, exercise test results were compared in 50 patients with stable angina and in 17 normal subjects with those in two groups known to have a high prevalence of inaccurate electrocardiographic responses to exercise. The last two groups included 51 patients tested within three weeks of acute myocardial infarction and 17 with important aortic regurgitation but no coronary disease. Of the normal subjects, 16 (94%) had ST/HR values less than or equal to 1 X 1 microV/beat/min. Of those with stable angina pectoris, 42 of 46 (91%) patients with coronary artery disease had ST/HR slopes ranging from 1 X 2 to 20 X 0 microV/beat/min, with false negative findings (slopes less than or equal to 1 X 1 microV/beat/min) in only four (9%). In contrast, of those with recent myocardial infarction, 15 of 42 (36%) with coronary disease had false negative slopes, including 12 of 20 (60%) with anterior wall injury. Of those with aortic regurgitation, conversely, 14 of 16 (88%) patients with calculable ST/HR slopes had values greater than 1 X 1 microV/beat/min despite the absence of coronary disease. Despite the accuracy of the test in patients with stable angina, false negative results are common in those after recent myocardial infarction, and false positive results occur often in those with abnormal volume loading due to aortic regurgitation.
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In recent years, exercise testing has become an increasingly important means of evaluating subtle symptomatic changes in patients with aortic and mitral valve disease. Perhaps more significantly, however, when employed with other objective indicators of cardiac function, exercise testing appears to be of value in identifying patients with clinically important deterioration of myocardial function and in assessing the efficacy of various forms of therapy. As investigation of the role of exercise testing in these patients continues, it seems likely that application of exercise testing will prove of value in the rational selection of patients for available therapy.
After his first acute myocardial infarction, a 69-year-old male suffered the usually lethal complication of ventricular free-wall rupture. Early suspicion of possible rupture and immediate percutaneous insertion of an intraaortic balloon pump assist device afforded sufficient hemodynamic stability to proceed with cardiac catheterization. The diagnosis of ventricular free-wall rupture was confirmed and the extent of coronary artery disease defined. The patient underwent repair of the free-wall rupture and coronary artery bypass grafting and has returned to full activity.
Information in 51 tape-recorded physician-patient encounters was compared with information written in the patients' medical records. Diagnoses, chief complaints, scheduled appointments, non-drug therapy, and diagnostic studies were uniformly well-recorded. Medication names were well-recorded but dosages were not. Characteristics of care such as levels of function, probable cause of illness, reason for follow-up, and compliance were recorded poorly. Patients were more likely to known about and understand their diagnosis, and names, dosage, and intended function of their medications when this information was written in the record than when it was not. These findings indicate a relationship between the quality of medical records and the effectiveness of care.
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