Relationship between systolic time intervals and arterial blood pressure

It has been suggested that systolic time intervals (STI) can be used to monitor the cardiac effects of antihypertensive treatments and also to evaluate hypertensive patients. STI changes observed in hypertensives have been ascribed to myocardial disease, although they could be due to the existence of a relationship between STI and blood pressure. A group of 37 subjects (18 normotensives and 19 hypertensives) with no signs of heart failure and left ventricular dysfunction were studied to examine the relationship of STI to blood pressure. Pacing with an external battery pulse generator was performed at the rate of 95 beats/min in order to eliminate differences in heart rate. STI were measured from good quality high speed (100 mm/s) recordings and the average value of 10 consecutive cardiac cycles was used for statistical analysis. Normal subjects showed significantly lower values of pre-ejection period (PEP), electromechanical systole (QS2), and pre-ejection period/left ventricular ejection time ratio (PEP/LVET). Moreover, a significant inverse relationship between diastolic pressure and LVET and significant direct relationships between diastolic pressure and PEP, systolic pressure and PEP, diastolic pressure and PEP/LVET, and between systolic pressure and PEP/LVET were demonstrated. We suggest to consider the relation of STI to blood pressure to provide regression equations to best appreciate and use STI.     

Systolic time intervals in dilated cardiomyopathy

Systolic Time Intervals (STI) were recorded in 45 patients with Dilated Cardiomyopathy (DCMY) to evaluate left ventricular function. Shortening of LVETI was seen in 37 (82%), prolongation of PEPI in 42 (93%), and increase in PEP/LVET ratio in 43 (95%) patients of DCMY. Global left ventricular dysfunction could be identified in all the patients (100%) with the combination of PEPI and PEP/LVET ratio. On follow up evaluation of 14 patients, change in STI status was seen to correlate with clinical status of the patients. STI as a non-invasive indicator of left ventricular function are useful in diagnosis and follow up of patients with DCMY.     

Heart failure in hypertensive patients with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is supposed to be a useful marker of cardiovascular complications during the course of hypertension. Authors compared the presence of heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in hypertensive patients with and without left ventricular hypertrophy defined by echocardiography. Hospital records of 192 hypertensives treated in our medical department during years 1996-1999 were analysed. Left ventricular hypertrophy was defined by echocardiography (Penn convention) as left ventricular mass index > 134 g/m2 in men and > 110 g/m2 in women. Presence of LVH was found in 128 patients (mean age 65.9 years), absence of LVH in 64 patients (mean age 64.8 years). Both groups of hypertensives were matched by demographic parameters, by the presence of hyperlipidemia, by smoking habits. Hypertensive patients with left ventricular hypertrophy were more often treated by ACE inhibitors. There were statistically significant more patients with heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in LVH-positive patients than in LVH-negative once. There was also statistically significant lower ejection fraction (50.3 +/- 11.4% vs 56.5 +/- 7.4%) in LVH-positive patients than in LVH-negative once. Left ventricular hypertrophy in patients with hypertension brings usually a complicated course of the disease with a high contribution to the development of chronic heart failure.     

Characteristics of systolic time intervals in patients with pheochromocytoma

The effect of chronic catecholamine excess on cardiac function was assessed in 8 patients with surgically proven pheochromocytoma and the results compared with data obtained from normal controls and essential hypertensives. Major findings in systolic time intervals (STI) in patients with pheochromocytoma were a marked shortening of electromechanical systole and left ventricular ejection time (ET), but pre-ejection period (PEP) remained within normal limits. These findings were not altered by correction for heart rate. The ET/PEP ratio was very low (1.87 +/- 0.31) due to the remarkable shortening of ET. The ET/PEP ratio in essential hypertensives was also low (1.77 +/- 0.38), but this was mainly due to a remarkable prolongation of PEP. Low cardiac index, low stroke index and high total peripheral resistance index were preoperative characteristics in patients with pheochromocytoma, but returned to normal after operation. These results suggest that chronic excessive production of catecholamines from pheochromocytoma has deleterious effects on the heart, and that wide differences in STI exist between patients with pheochromocytoma and those with essential hypertension.     

Echocardiographic estimation of pulmonary artery pressure in transposition of the great arteries

To determine their usefulness in estimating pulmonary artery pressure, left ventricular systolic time intervals (STI) were determined by echocardiography in 65 patients with dextro-transposition of the great arteries (TGA). The STI were measured from recordings of pulmonary valve motion at 100 mm/sec paper speed. The pre-ejection period (PEP) and the ratio of PEP to left ventricular ejection time (PEP/LVET) were directly related to pulmonary artery pressure. The strongest correlations were that between PEP/LVET and pulmonary artery diastolic pressure (r = 0.70) and that between PEP/LVET and the ratio of mean pulmonary pressure to mean systemic pressure (r = 0.71). A value of PEP/LVET of less than 0.26 was consistently associated with pulmonary artery diastolic pressures of less than 20 mm Hg and, in 28 of 31 patients, pulmonary artery pressure less than one-third of mean systemic arterial pressure. Pulmonary hypertension was present in 18 of 22 patients with PEP/LVET of 0.30 or greater; elevated PEP/LVET was also present in four patients with abnormalities of cardiac rhythm or conduction, two of whom also had angiographic evidence of myocardial dysfunction.     

The antihypertensive and cardiac hemodynamic effects of nebivolol.

Acute, subacute, and chronic treatment with nebivolol, a novel beta 1-selective adrenergic antagonist, significantly lowered systolic and diastolic blood pressure and heart rate in patients with essential hypertension. No orthostatism and bradycardia were reported. A comparison between a normal control group and 23 hypertensive patients revealed that the ratio between the preejection period (PEP) and the left ventricular ejection time (LVET) of the systolic time intervals (STI) was significantly increased in the hypertensive patients, owing to a prolongation of the PEPc (PEP corrected for heart rate). Treatment with nebivolol 5 mg once a day significantly improved the PEP/LVET, in acute conditions from 0.42 +/- 0.023 to 0.39 +/- 0.018, after one month of treatment from 0.40 +/- 0.013 to 0.36 +/- 0.013 and after one year of treatment from 0.41 +/- 0.012 to 0.36 +/- 0.010, owing to a significant shortening of the PEPc. There was no correlation between changes of blood pressure and changes of STI. Diastolic dysfunction is an early finding in hypertension and may well be reflected in the prolongation of the PEPc. The improvement of left ventricular performance, as measured with STI, suggests that treatment with nebivolol may favorably influence the underlying diastolic dysfunction and be of therapeutic value for hypertensive patients with left ventricular damage.     

Left Ventricular mass Regression with Amlodipine in Elderly Hypertensives

We evaluated effect of amlodipine therapy on left ventricular (LV) mass and function indices in 34 elderly hypertensives having echocardiographic evidence of left ventricular hypertrophy (LVH). LV mass and LV function indices were evaluated before and after 4 months of effective amlodipine therapy. Fourteen patients completed the study. Blood pressure was effectively controlled in all the patients; dose requirement of amlodipine being 5 mg/day in 8 and 10 mg/day in 6 patients. We found significant regression of LV mass indices such as thickness of interventricular septum (IVS) and left ventricular posterior wall (LVPW), and LV mass index after 4 months of amlodipine therapy. However, LV function indices did not alter following treatment. In conclusion, amlodipine therapy besides effectively contrlolling BP in elderly hypertensives, produced significant regression of LV mass indices without affecting the LV function.     

Left ventricular mass regression with amlodipine in elderly hypertensives

We evaluated effect of amlodipine therapy on left ventricular (LV) mass and function indices in 34 elderly hypertensives having echocardiographic evidence of left ventricular hypertrophy (LVH). LV mass and LV function indices were evaluated before and after 4 months of effective amlodipine therapy. Fourteen patients completed the study. Blood pressure was effectively controlled in all the patients; dose requirement of amlodipine being 5 mg/day in 8 and 10 mg/day in 6 patients. We found significant regression of LV mass indices such as thickness of interventricular septum (IVS) and left ventricular posterior wall (LVPW), and LV mass index after 4 months of amlodipine therapy. However, LV function indices did not alter following treatment. In conclusion, amlodipine therapy besides effectively controlling BP in elderly hypertensives, produced significant regression of LV mass indices without affecting the LV function.     

Non invasive evaluation of left ventricular performance in 294 diabetic patients without clinical heart disease

Summary The authors studied the modification of systolic time intervals (STI), pre-ejection period (PEP) and left ventricular ejection time (LVET _c ), before and after isometric exercise, in 294 diabetic patients without clinical evidence of cardiomyopathy and in good metabolic control compared to 132 normal subjects. The study was aimed at detecting preclinical alterations of left ventricular function. Diabetic patients considered together did not show any difference in STI in basal conditions or after isometric exercise compared to normal subjects. When diabetic patients were divided into sub-groups according to their treatment, the insulin-treated diabetics showed modification of STI after isometric exercise, which indicated an alteration of left ventricular function. Also subjects treated with oral hypoglycemic agents showed similar but less evident changes. In diabetic patients on diet only and in those with duration of diabetes of 6 months or less, STI was identical to that of normal subjects. These data do not explain the pathogenesis of myocardial involvement, although they are in accordance with studies which have laid emphasis on the alteration of compliance of the diabetic heart.     

Effects of propranolol and atenolol on plasma renin activity and systolic time intervals in borderline hypertension

Plasma renin activity (PRA) and systolic time intervals (STI), including total electromechanical systole (QS2), left ventricular ejection time (LVET), pre-ejection period (PEP) and isovolumetric contraction time (ICT), were measured in patients atenolol and propranolol. Both beta blockers caused a similar fall in blood pressure and heart rate (P less than 0.001). QS2, PEPc and PEP/LVET values did not change after treatment. Propranolol prolonged ICT (p less than 0.001) and reduced LVET (p less than 0.001). No significant changes were detected in PRA after atenolol while a reduction was found after treatment with propranolol (p less than 0.001). No relationship was found between PRA and STI, however a linear correlation was recorded between systolic pressure and PRA (r = 0,91; p less than 0.01) before beta-blockade. These results suggest that: a) only beta-adrenoceptors are involved in the release of renin; and b) the effect of beta-blockers on STI follows a reduction of blood pressure and heart rate which in turn affect afterload.     

Left ventricular filling abnormalities and obesity-associated hypertension: relationship with overproduction of circulating transforming growth factor beta1

This study has been designed to evaluate the relationship among transforming growth factor beta1 (TGFbeta1) and some measurements of diastolic function in a population of hypertensive subjects with normal left ventricular ejection fraction. We studied 67 hypertensive outpatients who according to their BMI levels were subdivided into three groups: lean (L), overweight (OW) and obese (OB) hypertensives (HT). Circulating TGFbeta1 and M- and B-mode echocardiography was determined. All hypertensives were further subgrouped, according to European Society of Cardiology Guidelines, into two subsets of patients with normal diastolic function or with diastolic dysfunction. Prevalence of left ventricular hypertrophy (LVH) was determined in all the groups. TGFbeta1, left ventricular mass (LVM), LVM/h(2.7), E-wave deceleration time and isovolumic relaxation time (IVRT) were significantly (P < 0.005) higher and E/A velocity ratio was significantly (P < 0.05) lower in OW-HT and OB-HT than in L-HT. Prevalence of LVH was significantly higher (P < 0.03) in group OB-HT than in L-HT. TGFbeta1 (P < 0.004), LVM/h(2.7) (P < 0.001) and prevalence of LVH were (P < 0.01) significantly higher in hypertensives with diastolic dysfunction than hypertensives with normal diastolic function. TGFbeta1 levels were positively correlated with BMI (r = 0.60; P < 0.0001), LVM/h(2.7) (r = 0.28; P < 0.03), IVRT (r = 0.30; P < 0.02) and negatively with E/A ratio (r = -0.38; P < 0.002) in all HT. Multiple regression analysis indicated that TGFbeta1, BMI and IVRT were independently related to E/A ratio explaining 71% of its variability (r = 0.84; P < 0.0001). This relationship was independent of LVH, age and HR suggesting that TGFbeta1 overproduction may be considered a pathophysiological mechanism in the development of left ventricular filling abnormalities in obesity-associated hypertension.     

Mechanocardiographic assessment of systolic time intervals in normal children

Summary Systolic time intervals (STI) were measured in 469 normal children, aged 5.0 to 16.9 years, using simultaneous recordings of the electrocardiogram, phonocardiogram and an external carotid pulse tracing. The data were analyzed to define the influence of sex, age, cardiac cycle length, body weight (BW), body length (BL), and body surface area (BSA) on the left ventricular STI. Regression equations were evaluated for the calculation of normal standards for the following STI: electromechanical systole (QS2), left ventricular ejection time (LVET), pre-ejection period (PEP), systolic quotient (PEP/LVET), isovolumic contraction time (IVCT), electroacustical delay (QS1), and additionally for the so-called tension time (TT), upstroke time (UT), and the ascending index (UT/LVET) of the carotid pulse wave. Heart rate was found to influence all of the STI but the ratio UT/LVET, which revealed to be independent of any variable. Besides heart rate, BSA proved to be a second relevant independent variable for QS2 and LVET, respectively BL for PEP, PEP/LVET and QS1. These findings are in accordance to the results of comparable echocardiographic studies but disagree previous mechanocardiographic studies in smaller groups of children in whom age and not the above-mentioned parameters of the individual development seemed to influence the STI.A second set of equations was evaluated for the calculation of 95%-prediction intervals for the particular STI permitting to define abnormalities of the STI in individual children.Supported by Stiftung Volkswagenwerk, Grant No. I/35708.     

Is blood pressure the major determinant of left ventricular mass in subjects over 50 years of age?

The weak relation of systolic blood pressure to left ventricular (LV) mass in hypertension has frequently been regarded as evidence of non-hemodynamic stimuli to muscle growth. Anyway, left ventricular hypertrophy (LVH) is associated with a significantly increased risk for cardiovascular events. Data were obtained from M-mode echocardiograms in 10 normotensives and 58 hypertensives over 50 years (range 50-85 years); 18 hypertensives; were without (LVH -) and 40 were with LVH (LVH +) - when LV mass, normalized for body surface area, was calculated according to the Penn's Convention. Cardiac output was derived by Teicholz formula for LV volumes. End-systolic stress/end-systolic dimension ratio (ESS/ ESD r), an index of myocardial contractility, was calculated as previously validated in the literature. We found that, in subjects ranging from 50 to 85 years of age, the presence of LV hypertrophy is not necessarily associated with raised blood pressure levels. Systolic function was substantially preserved among the study groups, irrespective of their age, hypertensive condition and/or presence of LVH. The increased wall thickness in subjects with LVH was associated with a significant reduction in wall stress (thus suggesting an adequateness of the compensatory role of LVH - at least at the observed stage of the hypertrophy process) and with a significant decrease of the contractile performance. On the multivariate analysis, the observed relation of LV mass to blood pressure and myocardial contractility (r = 0.621, P < 0.001) may explain some apparently conflicting findings, such as the lack of LV hypertrophy in a number of hypertensive patients.     

The applicability of systolic time intervals in patients before and after aortic valve replacement (author's transl)]

In order to evaluate the systolic time intervals (STI) for characterizing the left ventricular pump function and the clinical course in patients with aortic valve disease, 35 patients with aortic stenosis (AS) and 25 patients with aortic insufficiency (AI class III or IV (NYHA) were studied before and 1 year after valve replacement either with Bj?rk-Shiley, Lillehie-Kaster or Starr-Edwards aortic prostheses. Left ventricular ejection time index (LVETI), preejection period index (PEPI) and PEP/LVET were determined and compared with cardiac index (CI), stroke volume index (SVI) and ejection fraction (EF). Prosthetic valve replacement leads to a high significant decrease of LVETI from preop. 468 +/- 31 ms to postop. 394 +/- 26 ms (mean normal values 415 ms) and an increase of PEPI from 100 +/- 26 ms to 136 +/- 25 ms (normal 132 ms) as of PEP/LVET from 0.21 +/- 0.09 to 0.41 +/- 0.12 (normal 0.31). Pre- as well as postop. there is no difference in STI between AS and AI. Also the groups with the three prosthetic valve types do not differ significantly. LVETI and PEPI correlate only postop. with CI and SVI, but PEP/LVET correlates well with EF (r = -0.73) before and after operation. The comparison of STI with the hemodynamic data suggest that preop. values of STI near normal and postop. LVETI below, PEPI and PEP/LVET above the mean values of the whole group with aortic valve replacement indicate left ventricular pump dysfunction. The STI are helpful in the pre-/postop. follow-op of patients with severe aortic valve disease to characterize the clinical and hemodynamic course.     

Effects of ketanserin of left ventricular hypertrophy in hypertensive patients

Summary Ketanserin, a serotonergic S₂-receptor antagonist, was used in a prospective study in nine hypertensive patients with ECG criteria of left ventricular hypertrophy (LVH). Echocardiographic measurement with M mode was made after 1 month of placebo, and after 3, 6, and 12 months of ketanserin treatment as monotherapy at a mean dose of 31 mg bid. Ketanserin treatment decreased mean left ventricular mass by 9.3% at 3 months (not significant), by 15.3% at 6 months (p < 0.008), and by 26.2% at 12 months (p < 0.02), with a tendency towards improvement in left ventricular ejection fraction, which was not statistically significant. The study showed a sustained effect upon regression of LVH in hypertensives, with preservation of left ventricular function.     

The influence of the haemodynamic factor on the development of left ventricular hypertrophy in patients with arterial hypertension.

One hundred and forty-seven patients with essential hypertension (EH) and 126 patients with secondary arterial hypertension (AH) on the basis of chronic pyelonephritis were studied by means of radiocardiography with 131I-albumin and M-mode echocardiography. The importance of the haemodynamic type of circulation for the development of left ventricular hypertrophy (LVH) was established. Correlative analysis revealed that the influence of arterial pressure (AP) on LVH is increased by stabilization of AH, especially in patients with the normo- and hypokinetic types of circulation; interestingly, the relation between LVH and systolic pressure was closer than that between LVH and diastolic pressure, especially in patients with secondary AH. Moreover, it was shown that the development of LVH is due to a preferential increase in posterior wall thickness in essential hypertensives and in ventricular septal thickness in secondary hypertensives, although all patients with LVH had dilatation of the left ventricular cavity.     

Losartan controlled blood pressure and reduced left ventricular hypertrophy but did not alter arrhythmias in hypertensive men with preserved systolic function

The effect of antihypertensive therapy on arrhythmias is controversial. An initial study in patients with chronic heart failure indicated that losartan, an angiotensin II receptor antagonist, may possess antiarrhythmic properties. However, the effect of AT1 receptor antagonists on arrhythmias of subjects with good systolic function has never been evaluated. Thirty-nine men with primary hypertension (18 without left ventricular hypertrophy [LVH], and 21 with LVH, aged 48.2 +/-8.6 and 50.5 +/-6.0 years, respectively), 15 healthy normotensive subjects (47.9 +/-8.5 years), and 14 highly trained athletes (34.1 +/-1.6 years) were studied. Transthoracic echocardiography and 24-hour Holter ambulatory monitoring were performed at baseline (without treatment). Hypertensive patients underwent the same examinations after 8 months of losartan administration. The prevalence and complexity of ventricular arrhythmias, and the frequency of supraventricular arrhythmias were increased in hypertensive patients with LVH compared to normotensive controls and athletes, at baseline. A similar significant reduction of blood pressure (BP) was noted in both groups of patients (p < 0.001). The LVH was reduced in hypertensives with LVH (the left ventricular mass index by 12%, the interventricular septum by 8.1%, the posterior wall by 7%, all p < 0.01). However, the arrhythmias did not change in either group of patients, even if all hypertensives were considered as 1 group. In conclusion, an 8-month course with losartan was effective in lowering BP and reducing LVH. However, the increased arrhythmias, which were registered in hypertensive patients with LVH at baseline, did not change.     

Prevalence, characteristics and clinical correlates of left ventricular hypertrophy in stable hypertension. Echocardiographic study

251 in stable hypertensives were studied with M-Mode and two-dimensional echocardiography, in order to evaluate the prevalence of left ventricular hypertrophy (LVH), its patterns and clinical correlates. 54 subjects (21%) had been treated previously with antihypertensive drugs while the remaining 197 (79%) had not. A normal left ventricle was found in 69 subjects (27.1%; group A); a concentric LVH (h/r greater than or equal to 0.45) was found in 99 (39.4%; group B), while an eccentric LVH (left ventricular myocardial mass index greater than 140 g/m2, h/r less than 0.45) in 83 (43.1%; group C). An asymmetric LVH (septum to posterior wall thickness ratio greater than or equal to 1.3) was found in 33 subjects (3 did not fulfill the criteria for LVH, 21 had a concentric, and 10 an eccentric LVH). Mean age was significantly higher in group B as compared to groups A and C. The body mass index was comparable in all groups. Mean systolic blood pressure was significantly higher in groups B and C as compared to A. The duration and the severity of hypertension did not differ among the three groups. W.H.O. stage III was absent in group A, but no differences were found between group B and C as for W.H.O. stage distribution. We conclude that such factors as BMI, duration and severity of hypertension poorly correlate with the occurrence of LVH and its patterns. The fact that group B hypertensives were older than the others on average is against the hypothesis that eccentric hypertrophy follows the concentric pattern. Whether these two patterns represent separate entities in relation to different hemodynamic profiles deserves further investigation.     

Influence of exercise on QT dispersion in hypertensive patients with left ventricular hypertrophy without coronary artery disease

In hypertensive patients with left ventricular hypertrophy (LVH), the influence of exercise on the regional variations in ventricular repolarization is not well understood. The present study compared dispersions of QT and QT apex (QTD and QTaD), which are indices of regional variations in ventricular repolarization, between hypertensive patients with echocardiographic evidence of LVH and those without LVH. Seventy essential hypertensive patients underwent a modified Bruce protocol exercise test, and QTD and QTaD were measured at rest and at peak exercise level. All subjects had undergone coronary angiography and did not have coronary artery disease. None of them showed ST-segment depression during or after exercise. There were 20 patients with LVH and 50 patients without LVH. The QTD and QTaD at rest were not different between the patients with LVH and those without LVH (56+/-32 vs 57+/-28 ms, 52+/-20 vs 49+/-23 ms). At peak exercise level, QTaD was significantly decreased compared with the baseline in hypertensive patients without LVH (49+/-23 to 42+/-16ms, p<0.05), whereas in patients with LVH QTaD increased (52+/-20 to 67+/-17ms, p<0.05). QTaD at peak exercise level was positively correlated with the left ventricular mass index (r=0.357, p=0.0024). These data were unchanged after correction for heart rate using Bazett's equation. In conclusion, QTaD increased after exercise in hypertensive patients with LVH. Inhomogeneity of repolarization is induced by exercise stress in hypertensives with LVH.     

Presence and severity of carotid atherosclerosis in asymptomatic hypertension patients with left ventricular hypertrophy]

BACKGROUND AND PURPOSE: Arterial hypertension is associated with structural changes in the cardiovascular system. In hypertensives, a relationship has been found between left ventricular hypertrophy and carotid wall thickness, whereas the association with atherosclerotic plaque is less defined. The aim of this study was to evaluate the occurrence and severity of carotid atherosclerosis in hypertensive patients with or without left ventricular hypertrophy (LVH). MATERIALS AND METHODS: We studied 122 hypertensive subjects (62 men and 60 women), aged 60.1 +/- 12.1. Subjects were considered to have left ventricular hypertrophy if their left ventricular mass index (LVMI) at echocardiography exceeded 110 g/m2 in women and 135 g/m2 in men. Carotid intima-media thickness (IMT), external diameter and atherosclerotic plaques were evaluated by high resolution echo-color Doppler. RESULTS: IMT in both common carotid and bifurcation was significantly greater in hypertensives with LVH (p < 0.01), whereas external diameter did not differ significantly in the two groups. Increased presence (73.4 vs 32.8%) and severity (18.7 vs 5.2% for stenosis > 40%) of atherosclerotic plaque were found in the hypertrophic group. A weak but significant association was present among left ventricular mass index, ventricular wall thicknesses and carotid intima-media thickness, and plaque. CONCLUSIONS: In asymptomatic hypertensive subjects, LVH is associated with an increased risk of plaque formation and progression. Vascular hypertrophy may represent a distinct prognostic factor in hypertension and the association of cardiac and vascular hypertrophy may identify a group at high risk of future cardiovascular events.