Lea Boselli

Ultrasonographic Evaluation of Cardiac and Vascular Changes in Young Borderline Hypertensives

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensives (age 24 +/- 4 years) and in 20 normotensive subjects (age 23 +/- 6 years), as a control group. Both carotid axes have been scanned from different views on a transversal and longitudinal section. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mm Hg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2, p < 0.01 and p < 0.05 respectively). The intima-media thickness of both the CCA and BIF was significantly higher in borderline hypertensives than in normotensives (CCA 0.6 +/- 0.08 vs. 0.4 +/- 0.05 mm, p < 0.01; BIF 0.7 +/- 0.08 vs. 0.5 +/- 0.08, p < 0.01). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Altered blood pressure variability in patients with congestive heart failure

OBJECTIVE Congestive heart failure (CHF) is characterized by sympathetic overactivity but reduced variability of heart interval and sympathetic nerve activity; little information exists, however, about the alterations in blood pressure variability in this syndrome, especially during excitatory manoeuvres such as tilting or exercise. DESIGN AND METHODS Nine patients with CHF (age 62+/-1 years, NYHA class II-III, ejection fraction 33+/-1%, peak VO2 14.1+/-3.2 ml/min per kg body weight [mean +/- SEM]) and eight healthy control subjects (age 58+/-1 years) with normal left ventricular function were studied. Blood pressure (Finapres), R-R interval (ECG) and respiration (nasal thermistor) were recorded during 15-min periods of supine rest, 70 degree head-up tilting, submaximal bicycling exercise and post-exercise recovery. Total variance and the power of the spectral components of blood pressure (HF, respiratory-related; LF, 0.03-0.14 Hz; and VLF, 0.02-0.003 Hz) were measured. RESULTS Compared with control subjects, CHF patients have, first, a normal overall blood pressure variability during supine rest but a failure to increase this variability in response to head-up tilt and exercise; second, a suppressed LF spectral component of blood pressure at rest and in response to head-up tilt and exercise; and third, reappearance of LF blood pressure power during postexercise recovery. CONCLUSIONS In CHF patients, overall blood pressure variability and its LF spectral component are altered at rest and during sympathoexcitatory manoeuvres. Somewhat paradoxically, however, the depressed LF blood pressure power is partially restored during a 15-min recovery period, indicating that at least part of the CHF-related alterations of blood pressure variability have the potential to revert back towards normal under appropriate physiological circumstances.

Right ventricular wall thickness and function in hypertensive patients with and without left ventricular hypertrophy: echo-Doppler study

The structure and function of the right ventricle in arterial hypertension have been the subject of only a few reports. The present study evaluated the functional and structural changes in both left and right ventricles. Doppler and standard echocardiography were performed in 58 hypertensive patients (33 without and 25 with left ventricular hypertrophy). We concluded that right ventricular wall thickness is significantly increased in hypertensive patients compared with normotensive subjects, and that there is a significant, direct correlation between right and left ventricular thickness. Abnormalities in right and left ventricular filling, characterized by a reduction in early and an increase in late diastolic flow velocity, occur in hypertensive patients, and there is a direct correlation between late mitral and tricuspidal flow velocities and left and right ventricular thickness.

Resting and postexercise hemodynamic effects of carvedilol, a beta-adrenergic blocker and precapillary vasodilator in hypertensive patients.

Summary: Carvedilol is a recently developed antihypertensive drug that combines in the same molecule a nonselective &bgr;‐adrenoceptor blocking effect and a vasodilating precapillary activity. In our study, we have investigated the effects of carvedilol 25 mg b.i.d. on blood pressure, heart rate, and plasma noradrenaline in hypertensive patients at rest and during exercise after acute and repeated oral administration for 7 days. The daily average supine blood pressure of the 12 patients with essential hypertension was 178 ± 10/107 ± 3 mm Hg (means ± SD of 8 measurements in each patient) after placebo and was significantly (p < 0.01) reduced to 162 ± 17/99 ± 8 mm Hg on the first day and to 158 ± 15/96 ± 8 mm Hg on the seventh day of carvedilol treatment. Similar values were found in the upright posture. Heart rate was slightly but significantly lowered during acute and repeated administration. The exercise‐induced increase in systolic blood pressure was significantly reduced by carvedilol 25 mg b.i.d., while there was a nonsignificant reduction in the tachycardic response. There was a significantly greater rise in plasma noradrenaline during exercise on the seventh day of carvedilol treatment. Carvedilol significantly lowered blood pressure and heart rate at rest and the exercise‐induced rise in systolic blood pressure.

Nifedipine does not blunt the aldosterone and cardiovascular response to angiotensin II and potassium infusion in hypertensive patients.

The antihypertensive response of calcium antagonists of the dihydropyridine series, although accompanied by a significant increase in plasma renin activity (PRA), is generally not associated with a comparably significant rise in plasma aldosterone (PA). This has been suggested to be due to the adrenal glomerular cell responsiveness being dependent on calcium entry. To investigate this hypothesis, angiotensin II (All; 0.15, 0.375, and 0.750 μg/min, each step for 20 min) and KCl (30 mmol/50 min) were infused on separate days in 11 hypertensive patients kept at a constant daily intake of 100 mmol sodium and 40 mmol potassium, before and after 1 week of nifedipine treatment (20 mg b.i.d.). Supine blood pressure (BP) was significantly (p < 0.01 -p < 0.001) reduced after nifedipine treatment; supine PRA increased significantly (p < 0.01), while PA did not change significantly. No change in plasma potassium level was seen during nifedipine treatment. The dose-dependent mean BP rises induced by All were slightly blunted during nifedipine treatment, whereas the PRA decreases and the PA rises after the peak infusion were not significantly different before and during nifedipine administration. Potassium infusion had no significant effect on BP, and caused a significant and similar rise in PA before and during nifedipine administration, while PRA decrease was more pronounced after nifedipine treatment. As previously shown in normotensive subjects, and also in hypertensive patients, aldosterone responses to two major stimulants, such as All and potassium, do not appear to be blunted by treatment with a calcium antagonist.

Left Ventricular Diastolic Function in Athletes and Borderline Hypertensives with Mild Cardiac Hypertrophy

The aim of this study was to evaluate the diastolic function in athletes and in young borderline hypertensives with mild left ventricular hypertrophy. Left ventricular filling was assessed by echo Doppler measurement of transmitral flow velocity in 18 soccer players (age 22 +/- 4 years, left ventricular mass index, LVMI 136 +/- 12 g/m2), in 15 borderline hypertensives (age 21 +/- 3 years, LVMI 137 +/- 9 g/m2), and 20 normotensive subjects (age 22 +/- 4 years, LVMI 93 +/- 10 g/m2) as reference group. We found that left ventricular filling profile was similar in borderline hypertensives, in athletes and in normotensive subjects. These findings suggest that, at least in the early stage, mild cardiac hypertrophy secondary to borderline blood pressure elevation is characterized by indexes of diastolic function not different from those found in athletes with physiological hypertrophy.

Cardiac and Carotid Structure in Arterial Hypertension and in Hypertrophic Cardiomyopathy

The aim of this study was to measure intima-media thickness (IMT) of the common carotid artery (CCA) in patients with hypertrophic cardiomyopathy (HCM) and in hypertensive patients with left ventricular hypertrophy (LVH). We studied 73 subjects: 20 normotensive healthy subjects as control group (I); 20 patients with essential hypertension without LVH (II); 20 hypertensives with LVH (III), and 13 normotensive patients with HCM (IV). Each subject underwent a complete echocardiographic and vascular ultrasonographic study in order to assess left ventricular parameters and the IMT at the level of the CCA. Left ventricular mass index (LVMI) was significantly higher in groups III and IV than in groups I and II (156 +/- 18 and 157 +/- 31 vs. 94 +/- 14 and 98 +/- 10 g/m2, respectively, p < 0.01), while IMT was significantly greater in group III but not in the others [0.88 +/- 0.04 vs. 0.61 +/- 0.03 (I), 0.64 +/- 0.03 (II) and 0.61 +/- 0.04 (IV) mm, p < 0.01]. The correlation between LVMI and IMT was statistically significant within all the hypertensive patients (r = 0.48, p < 0.01) but not in the HCM group (r = 0.17, p = NS). The hypertensive patients with LVH showed structural alterations (related to hemodynamic and humoral factors) both at cardiac and vascular level while in patients with HCM the cardiac alterations (due to a genetic disorder) were not associated with changes at the level of the large arteries.

Effects of long-term blood pressure control on left and right ventricular structure and function in hypertensive patients

The functional and anatomical abnormalities of the right ventricle may occur in hypertensive patients with left ventricular hypertrophy (LVH). The present study was designed to assess the functional and structural changes in both left and right ventricles induced by chronic antihypertensive therapy. Doppler and standard echocardiography were performed in 10 hypertensive patients with LVH before and after 1 year of treatment with captopril alone (5 patients) or captopril plus nifedipine (5 patients). We found that the left ventricular mass index and right ventricular thickness were significantly reduced in all patients when compared with pretreatment values. Furthermore, the Doppler-derived diastolic filling indexes show a significant improvement of both ventricular chambers. Our data suggest that anatomical and functional changes induced by therapy in hypertensive patients are not limited to the left ventricle but also involve the right ventricle.

Cardiac Structure and Function before and after Acute and Chronic Verapamil Administration in Hypertensive Patients

The aim of this study has been to analyze the acute and chronic effects of oral verapamil on diastolic function indices, derived from Doppler echocardiography, and left-ventricular (LV) dimensions and mass, assessed by M-mode echocardiography, in hypertensive patients without LV hypertrophy. 12 patients with essential hypertension were studied in basal conditions and (1) after a single oral administration of verapamil 160 mg and placebo in a double-blind protocol and (2) over chronic treatment (12 months) with verapamil 240 mg/day. At baseline, the ratio between early and atrial-induced transmitral velocities (E/A ratio) was lower in patients than in 12 age-matched normal subjects (1.08 +/- 0.2 vs. 1.51 +/- 0.3, p less than 0.01). Acute verapamil administration significantly decreased arterial blood pressure (162 +/- 26/101 +/- 8 to 142 +/- 12/88 +/- 7 mm Hg, p less than 0.01 after 2 h) and increased the E/A ratio to 1.26 +/- 0.3 (p less than 0.05) after 3 h. No change in ventricular dimensions and heart rate was observed. After chronic therapy, we found a further increase in the E/A ratio in 10 responder patients (1.49 +/- 0.3, p less than 0.01). The LV mass index, that was higher than in normal subjects before the treatment (118 +/- 16 vs. 91 +/- 11 g/m2, p less than 0.01), was significantly reduced (100 +/- 17 g/m2, p less than 0.05 vs. basal, nonsignificant vs. normal subjects). Our results demonstrate that acute administration of verapamil only partially improves the abnormal indices of diastolic function in hypertensive patients, whereas chronic treatment, by reducing LV mass indices and blood pressure to normal values, can completely normalize the indices of LV diastolic filling.

Effect on resting blood pressure and blood pressure homeostasis of short-term administration of the alpha1-adrenergic receptor antagonist, trimazosin, in hypertension

SummaryThe effects of trimazosin on blood pressure and cardiovascular homeostasis were studied in 12 subjects with untreated essential hypertension of mild or moderate degree. After a 3-day placebo period, the subjects were given trimazosin at the dose of 50, 100, or 200 mg twice daily (7 am and 7 pm) according to a randomized, double-blind crossover protocol. Each treatment was prolonged for 3 days and separated from the subsequent treatment by a 2-day placebo period. Blood pressure (sphygmomanometery) and heart rate were measured at rest during various laboratory maneuvers on the first and third day of the initial placebo, on the first and third day of the drug periods, and on the second day of the intervening placebo periods. Compared to placebo values, trimazosin caused a reduction in systolic and diastolic blood pressure which was well sustained through the time between the morning and the evening administration of the drug and was accompanied by only a slight tachycardia. The antihypertensive effect was similar in the supine and up-right position and in both instances it was greater for the 100 or 200 mg twice daily dose than for the 50-mg twice daily dose. The pressor and tachycardic responses to cold pressor test and to isometric and dynamic exercise were unaffected by the various doses of trimazosin whose antihypertensive effect was therefore similarly evident at rest and during behaviorally occurring blood pressure rises. Trimazosin also left unchanged the blood pressure and heart rate adjustments to passive tilting, its only effect being a modest and asymptomatic reduction in systolic blood pressure when tilting was performed during the first day of its administration at the highest dose. It is concluded that 100 mg or 200 mg twice daily of trimazosin effectively reduced high blood pressure. Both initially and at a later stage these doses did not modify the blood pressure adjustment to tilting, thereby preserving blood pressure homeostasis.