Stamatios Stamatelopoulos

Catheter-Mounted Aortic Valves

Abstract Three types of catheter-mounted aortic valve were tested in a mock circulation system, and two of them were further tested in anesthetized dogs that had traumatic aortic regurgitation. The valves proved to reduce regurgitation effectively. The umbrella-shaped valve was further tested by phonocardiographic, cineangiographic, and pressure-flow curve studies. A nonsignificant decrease in coronary flow was found to be caused by this prosthetic valve. Since it can be easily inserted through an artery, the umbrella valve may be useful in patients in whom a thoracotomy for valve replacement is contraindicated.

Isolated clinic hypertension is not an innocent phenomenon: effect on the carotid artery structure.

This study examines the common carotid intimal-medial wall thickness (CCA-IMT) in untreated patients with elevated clinic blood pressure (BP) but normal ambulatory BP (isolated clinic hypertension, n = 22), in comparison with a group with elevated clinic and ambulatory BP (hypertensives, n = 41) and a group with normal clinic and ambulatory BP (normotensives, n = 17) readings. The three groups did not differ in age, male/female ratio, lipid profile, glucose tolerance test, or smoking habits. No difference existed in CCA-IMT values between the groups with hypertension (0.67 +/- 0.18 mm) and isolated clinic hypertension (0.68 +/- 0.14 mm), but the values in these two groups were significantly higher (one-way ANOVA; F = 8.09, P < .001) than in the group of normotensives (0.50 +/- 0.09 mm). The CCA-IMT did not correlate with clinic systolic or diastolic BP readings or with BP derivatives of 24-h ambulatory monitoring. Mean 24-h BP in the isolated clinic hypertensives did not differ from that in the normotensives, whereas both were lower than in the hypertensives. We conclude that changes in the CCA-IMT occuring in subjects with isolated clinic hypertension are equal to the changes in sustained hypertension, indicating that isolated clinic hypertension may not be a benign condition.

Pulse pressure in normotensives: a marker of cardiovascular disease

The purpose of the present study was to evaluate the relation of the systemic arterial pulse pressure and other parameters derived from the 24-h arterial blood pressure (BP) monitoring to the severity of coronary artery disease, carotid lesions, and left ventricular (LV) mass index in patients without arterial hypertension. One hundred ten patients with known coronary artery disease underwent coronary arteriography, 24-h arterial BP monitoring, and ultrasound imaging of the carotid arteries and the myocardium. Measurements of 24-h arterial BP monitoring (systolic, diastolic, and average BP, pulse pressure, abnormal values of systolic and diastolic BP, and heart rate), the severity of coronary heart disease (Gensini score), intima-media thickness (IMT) of the common carotid artery and LV mass index were determined in all patients. By univariate analysis, only 24-h pulse pressure was significantly related to the severity of coronary artery disease (P < .01), carotid IMT(P < .01), and LV mass index (P < .01). In a multivariate analysis, 24-h pulse pressure was also the best predictor of the severity of coronary lesions (P = .009), carotid IMT (P = .003), and LV mass index (P = .009). Gensini score was related (P < .01) to LV mass index and not to carotid IMT. In conclusion, systemic arterial pulse pressure derived from 24-h arterial BP monitoring is related to coronary artery disease, carotid IMT, and LV mass index independently of age or any other derivative of 24-h arterial BP monitoring, indicating that this parameter could be a marker of global cardiovascular risk.

24 h blood pressure profile affects the left ventricle independently of the pressure level. A study in untreated essential hypertension diagnosed by office blood pressure readings.

This work examines whether the 24 h blood pressure (BP) pattern per se might affect the left ventricular structure independently of the pressure level. One hundred subjects with abnormally high office BP readings who had never received any antihypertensive treatment were submitted to 24 h ambulatory BP monitoring and left ventricular echocardiographic assessment. They were classified into two groups, as follows: dippers (group 1), consisting of 46 subjects whose mean nighttime systolic BP was reduced by at least 10% in comparison to the corresponding daytime value, and nondippers (group 2), consisting of 54 subjects whose nighttime BP did not drop or was reduced by < 10%. Left ventricular mass and end-diastolic volume values, both normalized for body surface area, were significantly higher in nondippers (r = 3.12, P < .003, and r = 7.46, P < .001, respectively). The two groups did not differ in diastolic thickness of either intraventricular septum or left ventricular posterior wall (both values normalized for body surface area), in mean 24 h systolic or diastolic or average blood pressure, or in age. In conclusion, in untreated essential hypertension diagnosed on the basis of abnormal office BP readings, the higher incidence of left ventricular mass increase in subjects unable to reduce their blood pressure during the night was more due to left ventricular dilatation than to myocardial wall thickening. The effect of the 24 h BP profile on left ventricular volume appears to be independent of both the BP level and age.

Treating severe cardiogenic shock by large counterpulsation volumes

BACKGROUNDnIntraaortic balloon pumping is known to be ineffective in severe cardiogenic shock. The efficacy of balloon volumes larger than those commonly used is examined.nnnMETHODSnIn 18 dogs with severe experimental cardiogenic shock (systolic aortic pressure < 60 mm Hg, aortic flow < 45 mL.min-1.kg-1) the effect of three intraaortic balloon volumes (15, 30, and 45 mL) and a 60-mL paraaortic pump was examined.nnnRESULTSnThe 45-mL balloon covering the full length of the aorta induced the highest (+ 12.4 +/- 2.2 mL.min-1.kg-1; mean +/- standard error of the mean) and the 15-mL balloon the lowest increase in aortic flow (F = 14.6, p < 0.0001). Only the 45-mL balloon increased (p < 0.05) urine output and renal artery flow. The 60-mL paraaortic pump induced the highest (F = 10.72, p < 0.002) increase (+ 36.6 +/- 6.5 mL.min-1.kg-1) in aortic flow compared to the three balloons. An 80- to 100-mL paraaortic pump maintained the life of 3 patients in severe cardiogenic shock for 4 hours, 8 days, and 54 days, whereas a 40-mL conventional balloon was completely ineffective.nnnCONCLUSIONSnExperimental and clinical data indicate that the effectiveness of intraaortic balloon pumping in severe cardiogenic shock may be improved by increasing the volume of the balloon (i.e., until it fully occupies the aorta).

Effect of Hypotensive Drugs on the Circadian Blood Pressure Pattern in Essential Hypertension: a Comparative Study

To compare the effect of four drug groups on the ambulatorycircadian blood pressure (BP) pattern, amiloride hydrochlorothiazide,atenolol, nifedipine, and perindopril (5/50 mg/d, 100 mg/d, 40mg/d, and 4 mg/d respectively, for 14 days) were alternated in eachof 20 essential hypertension patients. Diuretics induced the largest (P<0.05) drop in mean 24-hour systolic BP (−12 mmHg, P < 0.001).Atenolol reduced only its standard deviation, and nifedipine reduced onlythe mean daytime systolic BP (P < 0.05). The mean 24-hour diastolic BPwas equally reduced by all drugs except nifedipine, which only reduced (P< 0.05) the mean daytime value. The mean 24-hour heart rate wasdecreased by atenolol (P < 0.001), increased by diuretics (P <0.05), and unchanged with perindopril, while nifedipine increased (P < 0.05) only its night-time value. In conclusion, diuretics were the strongest agents in reducing systolic BP, atenolol the only agent thatreduced variability, perindopril the only agent that did not affect theheart rate, and nifedipine reduced only daytime BP values.

Incidence of coronary disease in patients with gastroduodenal ulcer or upper gastrointestinal tract hemorrhage.

From the Department of Clinical Therapeutics, Athens University Medical School (Prof. B. Malamos), Athens, Greece. * This group, which constitutes the control group, includes patients taken from successive admissions, with the following admitting diagnoses: Anemia 111, neoplastic disease of the lymphatic system 217, osteoarthritis 178 and cancer (excluding female genital system and gastrointestinal tract) 98. A high incidence of coronary disease in patients suffering from gastroduodenal ulcer was found both, in post-naortenal-5 and in clinical6-lo studies. There

Scleroderma heart disease: An unusual cause of positive antimyosin cardiac imaging

Summary111In-antimyosin scintigraphy offers a valuable noninvasive method for early detection of clinically silent cardiac involvement in patients with systemic sclerosis, even in the absence of left ventricular dysfunction. In these patients with positive antimyosin study results, intense pharmacologic treatment with vasodilators may be warranted.

Left intraventricular balloon pump optimization during intractable cardiac arrest

This work aims to determine optimal balloon shape and volume during left intraventricular balloon pumping (IABP) in the fibrillating dog heart. A balloon volume equal to the left ventricular end-diastolic volume (LVEDV) maintained a higher systolic aortic pressure and flow (106.4 ± 2.7 mmHg and 84.7 ± 2.35 ml/kg/min, x ± SEM, respectively) than a 25% smaller (97.8 ± 3.3 mmHg, P=0.002 and 63.7 ± 4.1 ml/Kg/min, P=0.002, respectively) or a 25% larger balloon (87.4 ± 2.3 mmHg, P=0.002 and 70.9 ± 3.4 ml/kg/min, P=0.002, respectively). Among 5 different balloon shapes tested, a pear-shaped balloon inflated from the apex to the base of the left ventricle induced the highest (P varying from 0.042 to 0.01, compared to the remaining balloon shapes) systolic aortic pressure and flow (104.6 ± 4.5 mmHg and 77.9 ± 1.7 mg/kg/min, respectively). In conclusion, a pear shaped balloon, inflated to a volume equal to the LVEDV, from the apex to the base of the left ventricle, induced an optimal hemodynamic effect during LVBP.