From systole to diastole: will the detection of regional diastolic dysfunction allow recognition of coronary artery disease at an earlier stage?
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
The prolonged regional contractile failure of reperfused myocardium has usually been characterized in terms of systolic function, while only few reports on its diastolic function are available. None of these studies considered changes in the isovolumic diastole and the subsequent filling phase separately. Therefore, in the present study, the velocities of wall excursion during systole (Vsys), isovolumic diastole (Viso) and filling phase (Vfill) were determined in 12 anesthetized dogs. Additionally, post-ejection thickening (Pejt), a marker of left ventricular asynchrony, was determined. Measurements were performed under control conditions, during a 15 minute left circumflex (LCX) coronary artery occlusion (CAO) and at 10 minutes, 4 and 8 hours reperfusion. Heart rate, left ventricular pressure, and Vsys, Viso, Vfill, and Pejt of the anterior myocardium remained unchanged throughout the experiments. During CAO, systolic wall-thickening of the posterior wall was reversed to systolic wall-thinning. Upon reperfusion, Vsys started to recover (2.5 +/- 3.2 mm/s at 10 minutes) and gradually improved over 8 hours of reperfusion (4.6 +/- 3.2 mm/s at 4 hours, 6.4 +/- 1.5 mm/s at 8 hours). Viso became positive during CAO (9.4 +/- 7.1 mm/s vs. -5.6 +/- 3.9 mm/s under control conditions) and was unchanged at 10 minutes reperfusion (7.9 +/- 5.2 mm/s). After 4 hours and 8 hours of reperfusion, Viso recovered to 1.2 +/- 9.2 mm/s and -0.3 +/- 10.7 mm/s, respectively. Vfill also became positive during CAO (1.5 +/- 6.2 mm/s vs. -18 +/- 8.7 mm/s under control conditions). There was a quick recovery of Vfill (-9.4 +/- 7.5 mm/s) with the onset of reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
BACKGROUND: Active left ventricular relaxation, assessed by Doppler isovolumic relaxation time, is impaired in obesity. There is little information on left ventricular passive properties during filling. METHODS: To evaluate left ventricular late diastolic stiffness in obesity, Doppler echocardiographic interrogation of mitral inflow tract and pulmonary vein flow velocities were obtained from 47 normotensive, young obese subjects (11 males, 36 females) and 43 normotensive, young normal-weight volunteers (13 males, 30 females) of comparable age. RESULTS: After controlling the effect of blood pressure and left ventricular mass, isovolumic relaxation time was prolonged in obese subjects (p < 0.0001 vs normal-weight controls). No difference was found in transmitral peak early and late flow velocities. Obese subjects exhibited prolonged pulmonary vein reverse flow velocity during atrial contraction (p < 0.004), and a higher difference or ratio between duration of pulmonary reverse flow and duration of transmitral forward late flow (6 +/- 31 vs -20 +/- 39 ms or 1.06 +/- 0.3 vs 0.84 +/- 0.3, p < 0.002 and p < 0.001, respectively). These differences were also confirmed after controlling blood pressure and left ventricular mass. Non-invasively estimated left ventricular end-diastolic pressure was higher in obese subjects than in controls (p < 0.002). At multivariate analysis a higher body mass index was the sole predictor of prolonged difference between duration of pulmonary reverse flow and duration of transmitral forward late flow (beta = 0.38, p < 0.001). CONCLUSIONS: Obesity is associated with prolonged left ventricular active relaxation and abnormalities of filling pressure not detectable by the sole mitral inflow velocity pattern. These latter abnormalities are consistent with the presence of early increased left ventricular passive stiffness.
The objective of this study was to elucidate the relationship between left ventricular geometry and left ventricular (LV) function in patients with untreated essential hypertension. We evaluated LV systolic and diastolic functions by M-mode echocardiography in 24 normotensive control subjects (NC) and 129 patients with essential hypertension. Patients were divided into four groups according to the relative wall thickness and LV mass index: a normal left ventricle (n=57), a concentric remodeling (n=7), a concentric hypertrophy (n=31), and an eccentric hypertrophy (n=34) group. LV systolic function as measured by midwall fractional shortening (FS) was significantly decreased in both the concentric remodeling and concentric hypertrophy groups; no differences were observed for endocardial FS. LV diastolic function as measured by isovolumic relaxation time (IRT) was also decreased in both the concentric remodeling and concentric hypertrophy groups. In multivariate analysis, relative wall thickness (p<0.0001), end-systolic wall stress (p<0.0001), and systolic blood pressure (p=0.002) were independently associated (r2=0.72) with midwall FS in a model including age, LV mass index, body mass index, diastolic blood pressure and IRT. In addition, relative wall thickness (p=0.0008) and age (p<0.0001) were independently associated (r2=0.31) with IRT in a model including LV mass index, end-systolic wall stress, body mass index, systolic and diastolic blood pressures and midwall FS. We conclude that LV geometry as evaluated by relative wall thickness may provide a further independent stratification of LV systolic and diastolic functions in essential hypertension.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
OBJECTIVE: Continuous positive airway pressure (CPAP) by face mask is an effective method of treating severe cardiogenic pulmonary edema (CPE). However, to our knowledge, no study has provided a precise evaluation of the effects of CPAP on cardiac function in patients presenting with CPE and preserved left ventricular (LV) function. DESIGN: Prospective observational clinical study. SETTING: A 14-bed, medical ICU at a university hospital. PATIENTS: Nine consecutive patients presenting with hypoxemic acute CPE. INTERVENTIONS: All patients were selected for 30 min of CPAP with 10 cm H(2)O by mask with fraction of inspired oxygen adjusted for a cutaneous saturation > 90%. Doppler echocardiography was performed before CPAP application and during the last 10 min of breathing with CPAP. Two-tailed, paired t-tests were used to compare data recorded at baseline (oxygen alone) and after CPAP. MEASUREMENTS AND RESULTS: Four patients presented CPE with preserved left ventricular (LV) function (a preserved LV ejection fraction [LVEF] > 45%, and/or aortic velocity time integral > 17 cm in the absence of aortic stenosis or hypertrophic cardiomyopathy). Oxygenation and ventilatory parameters were improved by CPAP in all patients. Hemodynamic monitoring and Doppler echocardiographic analysis demonstrated that in patients with preserved LV systolic function, mean arterial pressure and LV end-diastolic volume were decreased significantly by CPAP (p < 0.04). In patients with LV systolic dysfunction, CPAP improved LVEF (p < 0.05) and decreased LV end-diastolic volume (p = 0.001) significantly. CONCLUSION: CPAP improves oxygenation and ventilatory parameters in all kinds of CPE. In patients with preserved LV contractility, the hemodynamic benefit of CPAP results from a decrease in LV end-diastolic volume (preload).
Left ventricular automatic border detection (ABD) patterns were defined in the parasternal short-axis and the apical four-chamber views and were compared with pulsed-wave diastolic Doppler flow-velocity patterns of the mitral valve in 49 subjects (aged 39 to 87 years), 10 selected normal individuals, and 39 consecutive patients with high-quality echocardiographic Doppler studies and relaxation abnormalities (Doppler peak early diastolic velocity/peak late velocity ratio < 1). Both short-axis and apical four-chamber views were useful in the assessment of diastolic function by ABD. However, in subjects with high-quality two-dimensional echocardiographic Doppler studies, ABD was technically more feasible in the apical four-chamber view (97%; 38/39 subjects) than in the short-axis view (64%; 25/39 subjects) and correlated better with Doppler parameters. Compared with normal subjects, patients with abnormal Doppler relaxation patterns showed significant differences in diastolic filling indexes obtained by the ABD technique. The ratio of peak rapid filling rate/peak atrial filling rate (PRFR/PAFR) obtained from the dA/dt waveform in the apical four-chamber view had the highest correlation with Doppler indexes (r = 0.79). A PRFR/PAFR ratio of 1.5 best discriminated between normal individuals and subjects with relaxation abnormalities, with high sensitivity and specificity (95% and 100%, respectively). The PRFR/PAFR ratio obtained from the dA/dt waveform seemed to be a simple and useful method to distinguish between normal and abnormal left ventricular diastolic filling, as defined by Doppler echocardiography.
Despite cardiac failure being a well recognised complication of thyrotoxicosis, systolic function has generally been reported as maintained or enhanced. In this study, left ventricular diastolic function was assessed in 16 thyrotoxic patients and 18 age-matched controls by pulsed-Doppler echocardiography. Patients were re-studied after 3 and 12 months of treatment. Prior to treatment all standard Doppler-derived indices of diastolic function were significantly different to control (isovolumic relaxation time (IVRT) 63 +/- 18.9 vs 84.0 +/- 14.8 ms, peak early filling velocity (Emax) 79.2 +/- 15.2 vs 61.9 +/- 10.7 cm.s-1, peak atrial filling velocity (Amax) 68.2 +/- 17.9 vs 42.2 +/- 9.4 cm.s-1, deceleration of early filling (E/F slope) 6.1 +/- 1.8 vs 3.7 +/- 1.1 m.s-1, thyrotoxic vs control). However, these filling abnormalities appear likely to reflect the tachycardia and reduced systemic vascular resistance (SVR) found in the patients (heart rate 102 +/- 15 vs 76 +/- 9, SVR 874 +/- 207 vs 1293 +/- 362 dynes.s-1 x cm-5, both P < 0.001). After 3 months of treatment haemodynamics were similar in the two groups but filling remained abnormal in patients with a pattern suggesting increased transmitral pressure gradients (Emax 73.1 +/- 15.1 cm.s-1, Amax 55.8 +/- 19.2 cm.s-1, E/F slope 4.9 +/- 2.0 m.s-1, all P < 0.05 compared to controls).(ABSTRACT TRUNCATED AT 250 WORDS)
We describe the case of a 48 year-old man whose Sorin bileaflet aortic prosthesis presented persistent systolic and intermittent diastolic failure due to fibrous tissue overgrowth in the left ventricular outflow tract.
In a relatively large population of patients with treated systemic hypertension and normal left ventricular systolic function, prevalence of abnormalities of left ventricular diastolic function, as assessed by Doppler echocardiographic study of mitral and pulmonary vein flow, was high, with 51% of patients showing indirect signs of increased left ventricular end-diastolic pressure. Furthermore, our data documented that a "normal" mitral flow profile does not exclude the presence of an abnormality of left ventricular filling, which could be otherwise identified by combined analysis of a pulmonary vein flow profile.
The heart and kidneys are important target organs in hypertension. Early signs of hypertensive target organ damage can be detected by evaluating left ventricular (LV) diastolic function and intrarenal hemodynamics using Doppler ultrasonography. However, it has not been sufficiently clarified whether cardiac damage and renal impairment progress in parallel, especially from the early stage. In the present study, Doppler echocardiography and renal Doppler ultrasonography were performed in 99 patients with treated essential hypertension, and LV diastolic filling parameters, ie., the velocity ratio of atrial filling to early diastolic filling (A/E), and the deceleration time of the E wave (DcT) and renal Doppler parameters, i.e., the diastolic to systolic ratio (D/S) and resistance index (RI), were determined. D/S was negatively correlated and RI was positively correlated with A/E and DcT. These cardiac and renal Doppler parameters were also associated with age, diastolic blood pressure, creatinine clearance, and/or glucose levels. By multiple regression analysis, D/S was found to have a significant association with DcT, independent of other clinical parameters, including age. In subgroup analysis in which patients were divided by their glucose tolerance, a significant correlation between renal Doppler parameters and LV diastolic function was observed in subjects with normal glucose tolerance, but this correlation disappeared in those with impaired glucose tolerance and diabetes mellitus. The present findings show that there is a significant relation between LV diastolic function and renal Doppler parameters in treated hypertensive patients, and suggest that cardiac damage progresses in parallel with renal involvement in these patients from the early stage.
BACKGROUND: Acute graft failure is an important cause of morbidity and mortality in cardiac transplantation, and it may be associated with myocardial changes that occur during brain death (BD). This study investigates the changes in biventricular systolic and diastolic function that occur after BD in a validated canine model. METHODS AND RESULTS: The hearts of 20 mongrel canines (23 to 31 kg) were instrumented with micromanometers, flow probes, and dimension transducers to measure minor/major axes as well as left and right ventricular (LV/RV) septum-to-free wall distances. LV/RV volumes were measured according to the shell subtraction method. LV/RV systolic function was analyzed by ventricular stroke work plotted versus end-diastolic volume during a caval occlusion (preload-independent recruitable systolic work, PRSW). The nonlinear relationships between diastatic pressure (stress) and LV/RV septum-to-free wall distances and volumes (strain) from successive diastoles during caval occlusion were used to evaluate LV/RV diastolic mechanics. The Cushing phenomenon, hyperdynamic response, and diabetes insipidus were observed in each animal after BD. Results are expressed as mean +/- SEM (P < .05 versus baseline, ANOVA, paired two-tailed Student's t test). Biventricular systolic function deteriorated significantly from baseline PRSW 6 to 7 hours after BD. The diastatic LV/RV pressure dimension relationships were significantly different after BD, indicating a decrease in ventricular chamber compliance during diastole. CONCLUSIONS: BD causes a significant loss of systolic and diastolic LV/RV function in the brain-dead, heart-beating cadaver, which may contribute to early postoperative cardiac graft failure in the recipient. These findings have significant clinical applications and may help to avoid suboptimal donor/recipient matches.
Explore the source record for details and available documents.