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PubMed1986

Doppler echocardiographic estimation of systolic pulmonary artery pressure in patients with aortic-pulmonary shunts.

The objective of this study was to determine if the pressure drop across various types of aortic-pulmonary shunts could be accurately estimated by Doppler echocardiography, and if systolic pulmonary pressure could be estimated by referencing the pressure drop across the aortic-pulmonary shunt to systolic systemic arterial pressure measured by cuff sphygmomanometry. This was done in 22 patients and Doppler results were compared with pulmonary artery pressure measured directly by strain gauge manometry. Adequate Doppler waveforms were obtained in 21 of 22 patients; 3 had a Waterston shunt, 10 had a Blalock-Taussig shunt, 1 had a left pulmonary artery-aortic anastomosis, 6 had a patent ductus arteriosus and 1 had an aortic-pulmonary window. Systolic pulmonary artery pressure estimated by Doppler echocardiography ranged from 12 to 90 mm Hg (mean 41.3 +/- 21.4 [SD] ), and measured by strain gauge manometry ranged from 20 to 90 mm Hg (mean 44.7 +/- 20.7) (p = NS, r = 0.94, SEE = 7.4 mm Hg; slope = 0.90, y intercept = 7.4 mm Hg). Systolic pulmonary artery to aortic pressure ratios predicted by Doppler recording ranged from 0.1 to 1.0 (mean 0.4 +/- 0.2 [SD] ); when calculated from direct measurement it ranged from 0.2 to 1.0 (mean 0.4 +/- 0.2) (p = NS, r = 0.92; SEE = 0.08, slope = 0.80, y intercept = 0.09). This study demonstrates that Doppler echocardiography provides an estimation of pressure drop across aortic-pulmonary shunts, and that the data can be used to estimate systolic pulmonary artery pressure by subtracting the estimated pressure drop from the systolic systemic arterial pressure.

Adolescent↗
PubMed1996

Systolic flow limitation in stenotic lower-extremity vein grafts.

PURPOSE: Our purpose was to investigate the hemodynamic theory that the blood flow rate through a stenotic arterial graft is limited by the onset of turbulence, which acts as a barrier at peak systole against further increases in systolic flow. METHODS: We used duplex ultrasonography to examine 25 stenotic infrainguinal vein grafts. Theory predicts that the flow limitation occurs at peak systole at a stenotic velocity greater than 250 cm/sec, which corresponds to a residual stenotic lumenal diameter of 0.36 cm (Reynolds No. 2000). These numbers are based on the assumption that the 68 ml/min blood flow is supplied by the femoropopliteal graft to the resting lower leg only during systole. When the lumen is smaller than 0.36, peak systolic velocity (PSV) must exceed 250 cm/sec. The increased velocity results in poststenotic turbulence. This turbulent condition restricts the average graft systolic flow to less than the 68 ml/min required by the lower leg, so diastolic flow is needed to make up the deficit. RESULTS: Twenty vein grafts with PSVs of 250 cm/sec or greater had end-diastolic velocities of 50 cm/sec or greater as predicted; three grafts with PSVs of 256 to 300 cm/sec and two grafts with PSVs of less than 250 cm/sec had no forward diastolic flow. CONCLUSION: The onset of turbulence in a stenotic vein graft supplying the lower leg occurs at a PSV of 250 cm/sec or greater. The appearance of diastolic flow maintains the average graft volume flow.

Blood Flow Velocity↗
PubMed2003

Doppler tissue analysis of mitral annular velocities: evidence for systolic abnormalities in patients with diastolic heart failure.

BACKGROUND: The presence of signs and symptoms of heart failure (HF), abnormal diastolic function and an ejection fraction > 45%, have been defined as diastolic HF (DHF). However, a cut-off value of 45% for ejection fraction seems arbitrary as mild systolic dysfunction may be overlooked. It was the goal of this study to assess the additive information derived from Doppler tissue imaging for patients with DHF. METHODS: As a measure of left ventricular (LV) long-axis function, systolic and diastolic velocities of the mitral annulus (peak, peak early, and peak late) derived from pulsed Doppler tissue imaging were assessed in 36 asymptomatic control subjects, 36 patients with DHF, and 35 patients with systolic HF (SHF). As a measure of overall LV performance, the Tei index (isovolumic contraction time and isovolumic relaxation time divided by ejection time) was assessed. RESULTS: In the DHF group, peak systolic annular velocity was reduced (7.1 +/- 1.2 cm/s) as compared with the control group (9.0 +/- 1.2 cm/s, P <.05), and was even lower in the SHF group (5.0 +/- 0.7 cm/s, P <.01 SHF group vs DHF/control groups). The Tei index was increased in the DHF group (0.53 +/- 0.14) in comparison with the control group (0.39 +/- 0.07, P <.05), and was highest in the SHF group (0.94 +/- 0.43, P <.01 SHF group vs control/DHF groups). Using peak systolic annular velocity < 7.95 cm/s as a cut-off value (derived from receiver operating characteristic curve analysis), patients with DHF were separated from control subjects with a sensitivity of 83% and a specificity of 83%. A Tei index > 0.43 separated patients with DHF and control subjects with a sensitivity of 79% and a specificity of 72%. CONCLUSION: Systolic long-axis LV function is also impaired in patients with DHF, resulting in feasible diagnosis of DHF by Doppler tissue imaging analysis of LV long-axis function and overall LV function with the Tei index.

Aged↗
PubMed2003

Systolic blood pressure is the main etiology for poorly controlled hypertension.

BACKGROUND: Isolated systolic hypertension is an important risk factor for cardiovascular events. The purpose of this study was to detect the prevalence of and to evaluate the effectiveness of currently available medications in the treatment of uncontrolled isolated systolic hypertension. METHODS: We randomly selected a total of 585 patients with hypertension from our database. The two most recent blood pressure (BP) readings and other data were obtained by chart review. RESULTS: Of 585 patients, 340 (58%) had controlled BP. Of 245 patients with uncontrolled hypertension, 77.1% had uncontrolled isolated systolic hypertension and the remaining 22.9% had uncontrolled diastolic hypertension. Patients with uncontrolled systolic hypertension were on average taking more antihypertensive medications than patients with controlled BP (2.10 +/- 0.09; P = .034). CONCLUSIONS: Systolic hypertension is the etiology of uncontrolled hypertension in the majority of patients. Currently available antihypertensive medications are less effective in controlling systolic hypertension.

Aged↗
PubMed1997

An effective approach for treating elderly patients with isolated systolic hypertension: results of an Italian multicenter study with fosinopril.

Cardiovascular diseases are the most common causes of mortality, and hypertension is the most common cardiovascular disease in all ages. The Systolic Hypertension in the Elderly Program (SHEP) trial has shown that the pharmacologic reduction of isolated systolic hypertension can significantly reduce the incidence of cardiovascular complications. The aim of the Italian multicenter study reported here is to compare the efficacy, safety, and tolerability of fosinopril, a novel angiotensin converting enzyme (ACE) inhibitor with a dual route of excretion, with chlorthalidone, the diuretic administered in the SHEP study, in 312 elderly patients with isolated systolic hypertension. Our results show that fosinopril and chlorthalidone produce identical and statistically significant reductions in systolic blood pressure (-23.9 +/- 11.6 mm Hg and -23.7 +/- 10.9 mm Hg, respectively) and, to a lesser extent, in diastolic blood pressure (-7.1 +/- 3.1 mm Hg and -5.2 +/- 2.3 mm Hg, respectively). Only chlorthalidone caused a statistically significant change in uric acid, total cholesterol, blood urea, and serum potassium concentrations. Fosinopril was also somewhat better tolerated than chlorthalidone. In conclusion, the novel ACE inhibitor fosinopril is an effective and well-tolerated antihypertensive agent for use in elderly patients with isolated systolic hypertension and appears to be a suitable alternative for the treatment of isolated systolic hypertension.

Administration, Oral↗
PubMed2003

The frequency of systolic versus diastolic heart failure in an Egyptian cohort.

BACKGROUND: All factors predisposing for congestive heart failure (CHF), such as coronary artery disease (CAD), hypertension and diabetes are increasing in prevalence in Egypt. Despite this, no data about CHF in our country are available. AIMS: To study the relative contribution of systolic vs. diastolic heart failure in Egyptians and the prevalence of risk factors in this population, as well as their prognosis. METHODS: This was a retrospective study of patients with a diagnosis of CHF over a 3.5-year period in a general cardiology clinic. Demographic, ECG and echocardiographic data for left ventricular systolic and diastolic function were collected. The differential effect of systolic versus diastolic CHF was analyzed regarding hospitalization and mortality. RESULTS: After exclusion of valvular diseases, we found 155 patients diagnosed with heart failure, 102 patients (66%) had systolic heart failure, and 53 (34%) had diastolic heart failure. Mean age was 60+/-10 and 63+/-11 years, respectively (P=0.13). Systolic CHF patients had significantly more CAD, while those with diastolic failure were mostly hypertensives (P<0.01) for both. There was no significant difference in the incidence of diabetes mellitus, cerebrovascular accidents or atrial fibrillation between the two groups. Patients with systolic failure required more hospitalization, P<0.05, and had a mortality rate of 17.6% vs. 11.3% for patients with diastolic heart failure (P=0.3). CONCLUSION: Diastolic heart failure is present in one-third of cases of CHF in Egyptians. Hypertension is very common in this group. These patients require less hospitalization but have a similar mortality rate.

Age Factors↗
PubMed2003

Headache as a predictive factor of severe systolic hypertension in acute ischemic stroke.

BACKGROUND: Elevation of blood pressure (BP) is common in acute cerebral infarction, with several studies reporting a high plasma catecholamine level or previous hypertension as a contributory factor. However, more comprehensive studies on associated clinical parameters are lacking. Our main aim in undertaking this study was to correlate clinical variables associated with a BP elevation in acute ischemic stroke. METHODS: Consecutive patients who were admitted to the emergency room and diagnosed with an acute cerebral infarction within 24 hours after the onset of symptoms were investigated. A BP elevation was defined as a high systolic (> or = 200mmHg) or diastolic (> or = 110 mmHg) pressure. The mean systolic and diastolic BP were compared between the different stroke subtypes, lesion locations (carotid vs. vertebrobasilar), and hemispheric sides. The frequency of symptoms, risk factors, location of the infarct, stroke severity, vascular status and laboratory abnormalities were analyzed in order to build a regression model. RESULTS: On hundred thirty-one patients were recruited (M:F = 60:71, mean age 66 +/- 12 years) and an elevated BP was identified in 33 patients (25.2%). The mean systolic and diastolic BP did not differ significantly between the stroke subtypes, lesion locations, and hemispheric sides. According to univariate logistic regression, an elevated systolic BP correlated with headache (p = 0.01) and underlying hypertension (p = 0.02) while an elevated diastolic BP correlated with underlying hypertension (p = 0.01). Multivariate logistic regression analysis revealed previous hypertension (OR 5.21, 95% CI 1.40-19.37) and headache (OR 4.09, 95% CI 1.44-11.66) to be independent predictors of an elevated systolic BP. CONCLUSIONS: Headache itself is closely associated with severe systolic BP elevation in acute ischemic stroke. Whether treatment of elevated BP improves headache and clinical outcome is not yet known, necessitating future controlled studies.

Aged↗
PubMed2001

Echocardiographic evaluation of right ventricular systolic functions in pure mitral stenosis.

Detailed echocardiographic evaluation of right ventricular muscle thickness and systolic functions was performed in twenty two cases of isolated rheumatic mitral stenosis without clinical signs of systemic venous congestion, tricuspid regurgitation or atrial fibrillation. Twenty two age and sex matched normal persons formed the control group. Right ventricular thickness was significantly increased in the patients with mitral stenosis. End-diastolic and end-systolic long axis measurements and areas were significantly increased and fractional shortening of these parameters was significantly reduced in the patient group. Our results show that right ventricular systolic functions are significantly impaired even in absence of clinical signs of systemic venous congestion. This impairment of systolic function did not correlate with pulmonary flow acceleration time. Myocardial involvement in rheumatic process could be one possibility. Systolic movement of the Tricuspid annulus and right ventricular mid cavity short axis dimension were not sensitive in detecting right ventricular systolic dysfunction.

Female↗
PubMed1999

Left atrial systolic function is depressed in idiopathic and preserved in ischemic dilated cardiomyopathy.

BACKGROUND: Left atrial systolic dysfunction, unexplained by altered loading conditions, has been reported in idiopathic dilated cardiomyopathy suggesting left atrial involvement in the myopathic process. MATERIALS AND METHODS: Seventeen patients with idiopathic dilated cardiomyopathy, 16 with ischemic dilated cardiomyopathy and 18 normal controls were studied with transthoracic echocardiography and cardiac catheterization. Transmitral diastolic flow was evaluated with pulsed Doppler. Left atrial volume (cm3/m2) at mitral valve opening (maximal, Vmax.), onset of atrial systole (P wave of the electrocardiogram, Vp), and mitral valve closure (minimal, Vmin. ) was determined with two-dimensional echocardiography using the biplane area-length method. The left atrial active emptying fraction (ACTEF = [Vp-Vmin.] x 100/Vp) served as an index of systolic function. RESULTS: The peak early diastolic transmitral flow velocity (cm/sec) was similar in the three groups (idiopathic: 60 +/- 16, ischemic: 58 +/- 20, control: 56 +/- 22; P = NS), whereas the late diastolic transmitral flow velocity was lower but not significantly different in idiopathic compared to ischemic cardiomyopathy, and in both was lower than control (26 +/- 12 vs. 34 +/- 13 vs. 44 +/- 14, respectively; P < 0.05). Vmax. and Vp were similar in idiopathic and ischemic cardiomyopathy and greater than control (44.6 +/- 13.6 vs. 48.2 +/- 18.3 vs. 26.9 +/- 6.2; P < 0.05, and 34.6 +/- 13.4 vs. 30.8 +/- 10.9 vs. 16.7 +/- 3.7, respectively; P < 0.05). ACTEF was lower in idiopathic than in ischemic cardiomyopathy and in the latter it was similar to control (18 +/- 10% vs. 32 +/- 10% vs. 36 +/- 10%, respectively; P < 0.05). Moreover, ACTEF was inversely related to left atrial tension at end-of atrial systole both in idiopathic and in ischemic cardiomyopathy (r2 = 0.52, P = 0.001 and r2 = 0.57, P = 0.0007, respectively). However, at any given level of left atrial tension at end of atrial systole, ACTEF was lower in idiopathic than ischemic cardiomyopathy. CONCLUSION: Left atrial systolic function is depressed in idiopathic and preserved in ischemic dilated cardiomyopathy despite similar left atrial loading conditions. This finding suggests left atrial myopathy in the former, and may be related to the differences in the response to medical treatment and clinical outcome observed between the two conditions.

Atrial Function, Left↗
PubMedDate not supplied

Systolic hypertension in hemodialysis patients.

Systolic hypertension with or without diastolic hypertension is a major problem in hemodialysis (HD) patients; isolated diastolic hypertension is uncommon. Accelerated age-related changes in vascular stiffness, together with factors peculiar to uremia, lead to loss of large and small vessel distensibility and profound changes in circulatory function that includes an increase in systolic pressure and widening of the pulse pressure. Epidemiologic studies show a direct relationship of mortality with systolic blood pressure (BP) and an inverse relationship with diastolic BP. Thus systolic BP should be the focus of treatment. In HD patients with systolic hypertension, diastolic BP is inversely related to cardiovascular risk. An accurate diagnosis of hypertension followed by nonpharmacologic measures (sodium restriction, exercise, dry weight) should be the initial steps in BP reduction. The second step should be the use of antihypertensive agents, particularly the use of angiotensin converting enzyme (ACE) inhibitors and/or beta-blockers. The use of these agents has been associated with better outcomes in observational studies in HD patients. Furthermore, the administration of atenolol and lisinopril can be supervised three times a week to achieve improved BP control. Daily dialysis may improve BP and cardiovascular risk factors. Although more difficult to implement, it may emerge as a feasible alternative to conventional dialysis. Adequate systolic BP control with these available and emerging techniques should help stem the tide of cardiovascular mortality and mortality in HD patients.

Comorbidity↗
PubMed2003

Assessment of left and right ventricular systolic and diastolic synchronicity in normal subjects by tissue Doppler echocardiography and the effects of age and heart rate.

OBJECTIVES: This study examined inter- and intraventricular synchronicity in systole and diastole by tissue Doppler imaging (TDI), and investigated if these parameters and the regional velocities were affected by age and heart rate. METHODS: TDI was performed in 106 normal subjects (64.3 +/- 9.5 years, 60% male) using three apical views and a six-basal, six mid-segmental model. The regional parameters measured off line in both ventricles included peak isovolumic contraction velocity IVC(M), peak sustained systolic velocity (SM), peak early diastolic velocity (EM), peak late diastolic velocity (AM), and the E/AM ratio, as well as their time to these peak velocities: T(IVC), T(S), T(E), and T(A). RESULTS: The systole and diastole within the left ventricle (LV) was highly synchronized without difference in T (IVC), TS, TE, and TA. However, the right ventricle (RV) was about 20 msec later than the LV for T(IVC) and TS. For regional velocities, IVC(M), S(M), E(M), and A(M) were significantly higher in basal than mid-segments (all P < 0.001). In the base of the LV, SM, and EM were the highest at the lateral segment and the lowest at the anterolateral segment. Age and heart rate did not affect systolic velocities or the timing of events. In diastole, age correlated negatively with EM(r =-0.36 to -0.48, P <or= 0.001)and E/AM ratio(r =-0.37 to -0.51, P <or= 0.01), while increasing heart rate affected AM (r = 0.17 to 0.43) positively and TE(r =-0.49 to -0.66, P < 0.001)and TA(r =-0.85 to -0.93, P < 0.001)negatively. CONCLUSION: (1). Systolic and diastolic functions of the normal hearts are highly synchronized, though LV contraction slightly preceded that of RV. (2). Age and heart rate predominantly affect the diastolic, but not systolic, parameters that need to be taken into account.

Age Factors↗
PubMed2000

N-terminal proatrial natriuretic peptide and prognosis in patients with heart failure and preserved systolic function.

BACKGROUND: Congestive heart failure and preserved left ventricular systolic function is a common clinical condition. Although the prognosis in this type of heart failure is better in comparison to systolic dysfunction, prognostic markers to evaluate long-term outcome are lacking. The atrial peptide, N-terminal proatrial natriuretic peptide (proANP), has been shown to predict survival in patients with systolic dysfunction. We intended to evaluate the predictive capability of N-terminal proANP in patients with preserved systolic function (ejection fraction [EF] > or = 0.40). METHODS AND RESULTS: A clinical and echocardiographic examination was performed in 149 patients with idiopathic heart failure from a population-based cohort, and 84 patients were identified to have preserved systolic function, with an EF of 0.40 or greater. The patients were followed up during 7 years with regard to symptoms, treatment, hospitalization, and survival. The patients with normal EFs had greater plasma concentrations of N-terminal proANP compared with a control group, and N-terminal proANP level was an independent predictor of mortality (risk ratio, 2.44; 95% confidence interval, 1.28 to 4.67; P = .007). In addition, a high concentration of N-terminal proANP predicted an increased rate of hospitalization (50% for a level > 1,200 pmol/L versus 19% for a level < or = 1,200 pmol/L; P = .046) and a greater future dosage of diuretic (127+/-102 vs 51+/-39 mg; P = .007). CONCLUSION: N-terminal proANP level was an independent marker of increased mortality and morbidity in patients with preserved systolic function, whereas EF was not usable in this regard. It is suggested that this peptide could be used to identify clinically relevant left ventricular dysfunction in patients with EFs within the normal range.

Aged↗
PubMed2002

Noninvasive estimation of both systolic and diastolic pulmonary artery pressure from Doppler analysis of tricuspid regurgitant velocity spectrum in patients with chronic heart failure.

BACKGROUND: Noninvasive estimation of pulmonary artery systolic and diastolic pressures usually requires the investigation of both tricuspid and pulmonary regurgitant jets and an estimate of right atrial pressure. A new, noninvasive method to obtain pulmonary diastolic pressure (based on the hemodynamic demonstration that right ventricular systolic pressure and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening) from the analysis of tricuspid regurgitation alone has been described in a small cohort of patients. We sought to verify the accuracy of this method in a large population of patients with heart failure. METHODS: An estimate of pulmonary artery diastolic pressure was obtained by transposing the pulmonary opening time (from the onset of the R wave on the electrocardiographic tracing to the beginning of pulmonic forward flow on Doppler examination) onto the tricuspid regurgitant velocity curve and calculating the pulmonary artery diastolic pressure value as the pressure gradient between the right ventricle and right atrium at this time. The study group included 86 consecutive patients (64 men, aged 52 +/- 11 years) with heart failure (New York Heart Association class > or =II, 94%) who were in stable clinical condition with a chiefly idiopathic (57%), ischemic (24%), or other form (13%) of dilated cardiomyopathy. Noninvasive, right-sided pressures were compared with invasive measurements obtained during right heart catheterization performed within 24 hours. The Bland and Altman graphic method was used together with the calculation of the Lin concordance correlation coefficient and its 95% CI to assess the agreement between hemodynamic and echocardiographic measurements. RESULTS: Catheter-derived pulmonary artery systolic pressure ranged from 8 to 119 mm Hg (mean 42 +/- 21 mm Hg), pulmonary artery diastolic pressure from 1 to 59 mm Hg (mean 20 +/- 11 mm Hg), and right atrial pressure from -5 to 20 mm Hg (mean 6 +/- 5 mm Hg). Tricuspid regurgitation was detected in 75 of 86 patients (87%). Pulmonary artery systolic pressure ranged from 13 to 110 mm Hg (mean 44 +/- 21 mm Hg); the pressure gradient between the right ventricle and right atrium at time t of the pulmonary valve opening on the tricuspid regurgitation velocity curve was measurable in 70 of 75 (93%) cases and ranged from 3.5 to 64 mm Hg (mean 22 +/- 11 mm Hg). Good agreement was observed not only for pulmonary artery systolic pressure but also for pulmonary artery diastolic pressure, based on the analysis of the tricuspid regurgitation velocity jet, with a slight difference between measurements (-1.8 and 0.1, respectively), no evident pattern of point scattering, and a high concordance correlation coefficient that was elicited by the virtually total overlapping of lines on the graph. Overall results were not significantly different whether patients with depressed right ventricular function (right ventricular ejection fraction < or =35%), with a tricuspid regurgitation grade > or =2 and atrial fibrillation were included in the analysis. CONCLUSIONS: The narrow paired difference for the estimate of pulmonary artery systolic pressure and the even better difference for pulmonary artery diastolic pressure using the tricuspid regurgitation velocity curve analysis indicates that this new method reliably estimates invasive right-sided pressures over a wide range of pressure values in patients with heart failure. The overall good correlation with invasive values indicates that Doppler examination of tricuspid regurgitation alone may provide a simple and comprehensive new method for the noninvasive evaluation of right ventricular and pulmonary hemodynamics in patients with heart failure.

Blood Pressure↗
PubMedDate not supplied

Differential systolic and diastolic effects of beta-adrenergic stimulation in patients with severe left ventricular dysfunction: a radionuclide ventriculographic study.

BACKGROUND: An attenuated inotropic response to beta-adrenergic stimulation has been documented in patients with severely depressed left ventricular (LV) function. Scant data exist regarding the effect of beta-adrenergic stimulation on LV diastolic function in human beings. Our objective was to evaluate the effect of dobutamine infusion on LV systolic and diastolic function in patients with severe ventricular dysfunction. METHODS AND RESULTS: We studied 26 patients (60 +/- 9 years) in stable condition with healed myocardial infarction and LV ejection fraction (EF) less than 35% by radionuclide ventriculography. LVEF, volumes, peak ejection rate (PER), peak filling rate (PFR), and peak systolic pressure-to-end-systolic volume ratio were calculated at the infusion rate of 5 and 10 gamma x kg(-1) x min(-1). At 5 gamma x kg(-1) x min(-1), no changes were observed in heart rate (75 +/- 16 beats/min vs 75 +/- 15 beats/min at rest), LVEF (23% +/- 8% vs 22% +/- 7%), and PER (1.40 +/- 0.48 end-diastolic volume per second [EDV/s] vs 1.30 +/- 0.48 EDV/s); however, a significant increase in PFR was observed (1.11 +/- 0.36 EDV/s vs 0.86 +/- 0.30 EDV/s, P < .01). At 10 gamma x kg(-1) x min(-1), an increase in LVEF (25% +/- 10%, P < .01) and PER (1.60 +/- 0.57 EDV/s, P < .01) was observed; PFR (1.25 +/- 0.36 EDV/s, P < .05) also increased, whereas heart rate (78 +/- 18 beats/min) was unchanged. No significant changes in LV volumes or in indices of LV contraction synchronicity were observed during infusion. Finally, the peak systolic pressure-to-end-systolic volume ratio was unchanged at 5 gamma x kg(-1) x min(-1) and significantly increased at 10 gamma x kg(-1) x min(-1). CONCLUSIONS: In stable patients with ischemic heart disease and severe LV dysfunction, beta-adrenergic stimulation may still induce a positive lusitropic response, despite attenuated inotropic and chronotropic responses; moreover, the effects on diastolic function occur earlier than those on systolic function.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Simulation of systolic and diastolic left ventricular dysfunction in a mock circulation: the effect of arterial compliance.

Arterial compliance (AC) is expected to play a major role on cardiac efficacy by acute or long-term mechanisms. The aim of this study was to investigate the purely mechanical effect of AC on left ventricular (LV) performance, for different conditions of LV dysfunction (systolic versus diastolic). A hydraulic, Windkessel model of systemic circulation was used. LV function and aortic flow were simulated using a left ventricular assist device (LVAD). Two cases of LV dysfunction were simulated: Case A, systolic and Case B, diastolic dysfunction. In Case A, AC increased from 1.14 to 2.85 ml mm Hg(-1) leading to an increase in LVAD stroke volume up to 6%, while no significant effect was observed in Case B. LVAD systolic work was decreased by 4% in systolic and by 11% in diastolic LVAD dysfunction. The purely mechanical effect of AC changes on LVAD function was different between systolic and diastolic dysfunction. It might be expected that even an acute reduction in arterial stiffness could enhance LV performance by different means in systolic compared to diastolic dysfunction.

Arteries↗
PubMed2003

Treatment of isolated systolic hypertension: the SHELL study results.

OBJECTIVE: Our aim was to compare the effect of lacidipine and chlorthalidone on cardiovascular outcome as a primary parameter and blood pressure as a secondary in elderly patients with isolated systolic hypertension in a prospective study with an open design. METHODS: 1882 males and females outpatients > or = 60 years were randomly assigned to the administration of chlorthalidone 12.5 mg o.d. or lacidipine 4 mg o.d. Patients were recruited if sitting systolic blood pressure was > or = 160 mmHg with a diastolic blood pressure equal or lower than 95 mmHg. Primary endpoint was a composite of cardiovascular and cerebrovascular events. RESULTS: At randomization mean systolic blood pressure was 178.1 mmHg in the lacidipine and 178.2 mmHg in the chlorthalidone group, the corresponding mean diastolic values being 86.9 and 86.8 mmHg. In both lacidipine and chlorthalidone groups treatment caused a significant (p < 0.001) and marked systolic blood pressure reduction which was maintained throughout the treatment period with a significant (p < 0.001) and steady although less marked reduction in diastolic blood pressure as well. At the end of treatment period (median 32 months), the reduction was 36.8/8.1 mmHg (systolic/diastolic) in the chlorthalidone and 38.4/7.9 mmHg in the lacidipine group, the final on treatment blood pressures being 142.0/79.2 and 143.2/79.5 mmHg, respectively. Treatments were similarly effective in males and females and in age groups between 60 and 69 years (n = 763), 70 and 79 years (n = 744) and > or = 80 years (n = 375). Similar reductions were obtained in a subgroup of patients (n = 209) followed in double-blind fashion for 1 year. The overall incidence of the primary endpoints was 9.3% with no significant between-group difference. Total mortality was also similar between groups. CONCLUSIONS: In elderly patients with isolated systolic hypertension, administration of lacidipine or chlorthalidone markedly reduced systolic blood pressure with no difference in the incidence of cardiovascular events and total mortality.

Aged↗
PubMed2006

A finite element model of the human left ventricular systole.

Local wall stress is the pivotal determinant of the heart muscle's systolic function. Under in vivo conditions, however, such stresses cannot be measured systematically and quantitatively. In contrast, imaging techniques based on magnetic resonance (MR) allow the determination of the deformation pattern of the left ventricle (LV) in vivo with high accuracy. The question arises to what extent deformation measurements are significant and might provide a possibility for future diagnostic purposes. The contractile forces cause deformation of LV myocardial tissue in terms of wall thickening, longitudinal shortening, twisting rotation and radial constriction. The myocardium is thereby understood to act as a densely interlaced mesh. Yet, whole cycle image sequences display a distribution of wall strains as function of space and time heralding a significant amount of inhomogeneity even under healthy conditions. We made similar observations previously by direct measurement of local contractile activity. The major reasons for these inhomogeneities derive from regional deviations of the ventricular walls from an ideal spheroidal shape along with marked disparities in focal fibre orientation. In response to a lack of diagnostic tools able to measure wall stress in clinical routine, this communication is aimed at an analysis and functional interpretation of the deformation pattern of an exemplary human heart at end-systole. To this end, the finite element (FE) method was used to simulate the three-dimensional deformations of the left ventricular myocardium due to contractile fibre forces at end-systole. The anisotropy associated with the fibre structure of the myocardial tissue was included in the form of a fibre orientation vector field which was reconstructed from the measured fibre trajectories in a post mortem human heart. Contraction was modelled by an additive second Piola-Kirchhoff active stress tensor. As a first conclusion, it became evident that longitudinal fibre forces, cross-fibre forces and shear along with systolic fibre rearrangement have to be taken into account for a useful modelling of systolic deformation. Second, a realistic geometry and fibre architecture lead to typical and substantially inhomogeneous deformation patterns as they are recorded in real hearts. We therefore, expect that the measurement of systolic deformation might provide useful diagnostic information.

Computer Simulation↗
PubMed1983

Reproducibility of the systolic time intervals: effect of the temporal range of measurements.

The aim of this study was to evaluate the reproducibility of conventionally measured systolic time intervals. To that end, three to eight serial measurements were performed on four different groups of healthy subjects (total number, 49) within dissimilar time periods: 1) within 3 h; 2) within 24 h; 3) within 1 to 2 weeks; and 4) within 14 to 18 months. Judged as the mean coefficients of variation, the variability of the systolic time intervals tended to be smallest in the 3 h measurements and largest in the 24 h measurements. The pooled variances of the serial measurements made within 24 h were in general significantly larger than the respective variances in the measurements made within 3 h. This was due to statistically significant diurnal decreases in left ventricular ejection time and total electromechanic systole in the 24 h study. Otherwise the reproducibility of the method was high. For instance, the mean coefficients of variation for ejection time and total electromechanic systole corrected for heart rate were only 1% and 1.2%, respectively, in serial measurements made at identical diurnal time points within 14 to 18 months. The pooled variances of the measurements made within the shortest and longest temporal ranges were not statistically different. It is concluded that measurement of the systolic time intervals is very applicable to intervention and follow-up studies provided the normal circadian rhythmicity of the phases of systole is adequately taken into account in the design of the study.

Adult↗