Abnormal blood-pressure response to exercise and oxygen consumption in patients with hypertrophic cardiomyopathy.

BACKGROUND: Abnormal blood-pressure response during exercise occurs in about one third of patients with hypertrophic cardiomyopathy (HCM), and it has been associated with a high risk of sudden cardiac death. We assessed the hemodynamics of exercise in HCM patients with abnormal blood-pressure response by using ambulatory radionuclide monitoring (VEST) of left-ventricular (LV) function, and exercise tolerance by oxygen consumption. METHODS: Twenty-two HCM patients underwent treadmill exercise during VEST monitoring. A cardiopulmonary exercise test was performed a few days after. The VEST data were averaged for 1 minute. Stroke volume, cardiac output, and systemic vascular resistance were expressed as percent of baseline. Exercise tolerance was assessed as maximal oxygen consumption. RESULTS: In eight HCM patients (36%) with an abnormal blood-pressure response, end-systolic volume increased more (52% +/- 21% vs 31% +/- 28%, P = .012), and the ejection fraction (-31% +/- 17% vs -14% +/- 22%, P = .029) and stroke volume (-21% +/- 21% vs 3% +/- 28%, P = .026) fell more, than in patients with normal response. Cardiac output increased less in the former patients (49% +/- 44% vs 94% +/- 44%, P = .012). Systemic vascular resistance decreased similarly, irrespective of blood-pressure response (-28% +/- 26% vs -34% +/- 26%, P = N.S.). Percent of maximal predicted oxygen consumption was lower in HCM patients with an abnormal blood-pressure response (63% +/- 11% vs 78% +/- 15%, P = .025). CONCLUSIONS: In HCM patients, abnormal blood-pressure response was associated with exercise-induced LV systolic dysfunction and impairment in oxygen consumption. This may cause hemodynamic instability, associated with a high risk of sudden cardiac death.     

Ectasia of the ascending aorta at the time of aortic valve surgery: replace or relax?

BACKGROUND: The fate of aortic ectasia associated with aortic valve disease is usually derived from the natural history of primitive aortic aneurysm. We evaluated the evolution of untreated aortic dilation following aortic valve replacement and analyzed risk factors for expansion. METHODS: Thirty-eight patients undergoing aortic valve replacement, with an aortic diameter 40 to 55 mm, were followed up for a mean of 42 +/- 28 months (median 36 months). Freedom from adverse events, velocity of aortic expansion and correlation between velocity and several potential risk factors were evaluated. RESULTS: The mean aortic diameter did not change over time (43 +/- 4 vs 44 +/- 12, p = NS). Velocity of aortic expansion correlated significantly with the diameter of the ascending aorta at the time of operation, with faster growth in patients with ascending aorta diameter > 50 mm (p = 0.0004). Patients with aortic regurgitation had a tendency to a faster aortic dilation compared to those with aortic stenosis (p = 0.10). CONCLUSIONS. In patients without other risk factors, prophylactic surgical treatment of the ectasic aorta seems advisable for diameters > 48 mm. For diameters < 43 mm no treatment is probably needed. Other aspects must be considered for appropriate surgical strategy in the interval between 43 and 48 mm. Patients with aortic regurgitation should be closely monitored.     

Exercise-induced changes of left ventricular ejection time in noninvasive evaluation of chest pain

Significance and clinical usefulness of exercise-induced changes of noninvasive left ventricular ejection time, recorded by mechanocardiography, in detecting coronary artery disease is still controversial. We investigated the changes of the left ventricular ejection time (LVET), corrected for heart rate as ETI (LVET/square root RR), after a standard 4-min exercise by bicycle ergometer (50 W/min for 2 min, increased by 20 W after 2 min) in 56 male volunteers. They were invasively studied for typical or atypical chest pain. Thirty-four had coronary artery disease (CAD) and the others served as controls. Immediately after exercise LVET shortened according to the rise in heart rate in both groups. ETI increased similarly. After 2 minutes from exercise ETI increased only in the CAD group, according to a longer LVET, in spite of the rise in heart rate. In contrast, ETI was unchanged in controls, according to a shortened LVET. Totally, 27/34 CAD patients and 9/22 controls had a greater ETI than at rest. Employing this delta ETI as a "marker" of CAD we found a predictive accuracy of 74%. We suggest postexercise ETI could be a simple and inexpensive support to electrocardiogram in basic evaluation of subjects with chest pain.     

Abnormal systolic time intervals in obesity and their relationship with the amount of overweight

We studied 17 severely obese subjects (age range 26 to 42 years), without hypertension, diabetes mellitus, angina, or clinical signs of heart failure or respiratory disease, and 16 age-matched control subjects. X-teleroentgenographic findings (transverse cardiac diameter and cardiothoracic ratio), blood pressure, and mechanocardiographic parameters were analyzed in both groups. By means of conventional simultaneous recordings of ECG, phonocardiogram, and carotid pulse (100 mm/sec), systolic time intervals were calculated as mean values from 10 beats in the morning. The following comparisons were made by means of analysis of variance: heart rate, preejection period (PEP), rate-corrected PEPI (PEPI), left ventricular ejection time (LVET), and QS2 interval (QS2); the latter two were both corrected for heart rate, respectively, as LVETI and QS2I and the PEP/LVET ratio. Abnormal x-ray data were shown in the obese group along with higher values for heart rate, PEP, PEPI, and PEP/LVET and a shorter LVETI; there were no differences in QS2I or blood pressure. There was a correlation between the amount of overweight and, respectively, transverse cardiac diameter (r = 0.84), heart rate (r = 0.69), PEP (r = 0.49), PEPI (r = 0.59), LVETI (r = -0.61), and PEP/LVET ratio (r = 0.72). A correlation was also found between transverse cardiac diameter and PEP/LVET (r = 0.67). We conclude, therefore, that abnormalities in the mechanocardiographic parameters are related to cardiac enlargement, suggesting a preclinical cardiac dysfunction secondary to chronic cardiocirculatory overload in severe obesity. Thus systolic time intervals appear to be affected by preclinical abnormalities of cardiac performance in these subjects.     

196. Aktive bakterielle Endokarditis und ihre Klappenkomplikationen -Chirurgische Ergebnisse bei 225 Patienten

Zusammenfassung 225 Patienten wurden wegen aktiver bakterieller Endokarditis oder der Klappenkomplikationen operiert. Die Frühmortalität betrug 12%. Bei 16 Patienten kam es zur Prothesendehiszenz - davon überlebten 6 Patienten die notfall mäßige Reoperation und 7 Patienten verstarben -, eine Indikation zu ausgedehnter Resektion des erkrankten Gewebes. Das mittlere Operationsalter betrug 43 Jahre. Auf Grund der vorliegenden Daten darf angenommen werden, daß die Mortalität durch eine kombinierte klappenchirurgische- und Coronararterien-Operation - falls indiziert-weiter gesenkt werden kann.     

Congenital absence of the pericardium associated with atrial septal defect and sick sinus syndrome

We describe the case of a 42-year-old woman with a rare combination of congenital pericardial absence, atrial septal defect within the fossa ovalis and sick sinus syndrome. The features of the different examinations performed (chest X-ray, ECG, ambulatory ECG-monitoring, echocardiography, and cardiac catheterization) are reported and discussed.     

Pacemaker malfunction due to subcutaneous emphysema--a case report.

The authors describe a cas of pacemaker malfunction due to a critical increase of impedance resulting from air entrapment in the pacemaker pocket.