Diastolic Transmitral Flow Research Articles

Relationship of Cardiac Hypertrophy and Diastolic Dysfunction Assessed by Echocardiography with Atherosclerosis in Retinal Arteries in Hypertensive Patients

Although left ventricular (LV) hypertrophy and diastolic dysfunction assessed by echocardiography are established risk markers of cardiovascular events in hypertensive patients, relationships between these echocardiographic findings and atherosclerosis have not been fully elucidated. The purpose of this study was to examine the relationships between atherosclerosis of the retinal arteries and echocardiographic findings in hypertensive patients. Forty hypertensive patients were divided into two groups according to Scheie's classification by ophthalmologists: 20 patients with stage 1 changes (visible broadening of the light reflex from the artery with minimal arteriovenous compression) and 20 patients with stage 2 changes (more prominent than those in stage 1). Standard echocardiography was performed to measure LV mass index for evaluating LV hypertrophy and conventional diastolic transmitral flow velocities for assessing LV diastolic function. Mitral annular velocities were also measured for evaluating LV diastolic function using tissue Doppler echocardiography. The LV mass index was larger in stage 2 (130 ± 39 g/m2) than stage 1 (96 ± 16 g/m2) patients (p = 0.001). Peak early diastolic mitral annular velocity (E′) was lower in stage 2 (5.9 ± 0.9 cm/s) than stage 1 (7.9 ± 1.7 cm/s) patients (p = 0.001). The optimal cutoff points for the diagnosis of Scheie stage 2 were 6.6 cm/sec for E′ (sensitivity 75%, specificity 85%) and 111 g/m2 for LV mass index (sensitivity 70%, specificity 90%). In conclusion, in hypertensive patients, the extent of atherosclerosis in the retinal arteries can be estimated by LV hypertrophy and diastolic dysfunction assessed by echocardiography.

Diastolic dysfunction types in the prediction of viable myocardium functional recovery

It is well known that patients with coronary artery disease and viable tissue as a guarantee of contractile recovery (CR), despite of decreasing ejection fraction (EF) and systolic dysfunction, could have benefit from surgical revascularization. Therefore, relationship between diastolic filling type and early postoperative recovery and complications need to be established. The aim of this study was to investigate the relation between different left ventricular (LV) diastolic filling types and CR in patients after surgical revascularization with differently preserved systolic function. We investigated 60 patients. All of them had CR estimated by stress echocardiography regardless the extent of recovery of the heart systolic function. Echocardiographic evidence of diastolic dysfunction was estimated by Doppler examination of transmitral diastolic flow. According to the derived different diastolic filling types the patients were divided into three groups: I--patients with disorder of LV relaxation, II--with pseudovascularisation, and III--with restrictive filling type, and according to the value of systolic function into two subgroups: (1) relatively recovered systolic function--EF > 40% and (2) pronounced LV dysfunction--EF < 40%. Echocardiographic evaluation was performed before and two week after surgical revascularization. In the preoperative period the medication therapy was optimized. We estimated CR by echocardiografic pare meters but also by detection of cardiovascular events. After CABG the mean value of WMISI LV tended to decrease in any groups: in the group I (n = 12) from 1.64 +/- 0.22 to 1.34 +/- 0.22; in the group II (n = 22) from 1.85 +/- 0.16 to 1.53 +/- 0.42, and in the group III (n=26) from 1.92 +/- 0.29 to 1.81 +/- 0.52. The lowest improvement of systolic function according to EF value expressed by the number of patients was found in the group of patients with restrictive LV filling type (12; 53.8%) as contrasting to the group with pseudonormalisation (15; 78.9%). In the group of patients with restrictive diastolic filling type also was recorded the highest number of lethal outcomes (6; 23.1%), as well as cardiovascular complications (10; 38.5%). Restrictive LV diastolic filling type was the marker of poor prognosis in the patients with clinical heart failure undergoing surgical revascularization. The patients with heart failure and preserved systolic function were associated with similar prognosis.

Evaluation of Left Ventricular Filling Pressures by Doppler Echocardiography in Patients With Hypertrophic Cardiomyopathy

Diastolic dysfunction is a major pathophysiological abnormality in hypertrophic cardiomyopathy (HCM). Doppler echocardiographic parameters correlate with left ventricular (LV) filling pressures in other diseases, but it is unclear whether these findings apply to patients with HCM, who have multiple complex interrelated events leading to diastolic dysfunction. This study compares Doppler echocardiographic estimates of filling pressures to direct measurements of left atrial pressure (LAP) via catheterization in 100 patients with HCM. One hundred patients who were symptomatic with HCM (New York Heart Association class III/IV, 82%) underwent measurement of early diastolic transmitral flow velocity (E) and mitral annular velocities (e') with the use of transthoracic echocardiography within 48 hours of cardiac catheterization with direct measurement of LAP. In a subset of 42 patients, echocardiographic and catheterization measurements were performed simultaneously. Mean LAP directly correlated with medial E-e' ratio in the overall population (r=0.44, P<0.0001) and also in the subgroup of patients who had simultaneous echocardiographic and catheterization studies (r=0.28, P=0.07). However, scatter was present. A calculated mean LV filling pressure was derived from the E-e' ratio with the use of a previously described regression equation, and the 95% confidence limits of agreement with measured mean LAP exceeded +/-18 mm Hg both for the overall group and for the subgroup who had simultaneous studies. Similar results were obtained with the lateral E-e' ratio. Only 1 patient had a previously defined "normal" E-e' ratio of <8. In symptomatic patients with HCM, Doppler echocardiographic estimates of LV filling pressure with the use of transmitral flows and mitral annular velocities correlate modestly with direct measurement of LAP. Given the complex nature of diastolic dysfunction in HCM, precise characterization of LV filling pressure in an individual patient cannot be determined with the use of these noninvasive parameters.

Tissue Cardiovascular Magnetic Resonance Demonstrates Regional Diastolic Dysfunction in Remote Tissue Early After Inferior Myocardial Infarction

To investigate regional diastolic and systolic function using tissue cardiovascular magnetic resonance (CMR), early after transmural myocardial infarction of the inferior wall due to single proximal right coronary artery disease. Velocity encoded CMR was used to measure early diastolic transmitral flow velocity (E), and regional, longitudinal, myocardial systolic (Sa) and early diastolic (Ea) velocities (tissue CMR) in 15 patients with a recent transmural inferior myocardial infarction and in 15 age and LV-mass index matched control subjects. An unpaired two-tailed t test was used to assess significance of continuous variables. Global systolic (ejection fraction 46 +/- 7% versus 57 +/- 4%, p = 0.000052) and global diastolic LV function (average Ea of infarcted or inferior, remote or anterior, adjacent or septal and lateral myocardium 6.8 +/- 1.7 cm/s versus 10.4 +/- 1.5 cm/s, p = 0.0000012) were impaired in patients as compared to controls. Regional systolic and diastolic LV velocities were impaired in infarcted and adjacent tissue in patients. However, in remote or anterior tissue, systolic velocities were preserved (Sa 6.6 +/- 2.0 cm/s versus 6.8 +/- 1.4 cm/s, p = 0.70), but diastolic velocities were impaired in patients as compared to controls (Ea 7.2 +/- 2.3 cm/s versus 10.2 +/- 2.5 cm/s, p = 0.0026). Regional diastolic velocities early after inferior myocardial infarction are impaired in the infarcted, adjacent and remote tissue, but regional systolic velocities are preserved in remote tissue.

Arterial Stiffness Is Associated With Left Ventricular Diastolic Function in Patients With Cardiovascular Risk Factors: Early Detection With the Use of Cardio-Ankle Vascular Index and Ultrasonic Strain Imaging

Background It is well known that left ventricular (LV) diastolic function declines in the elderly, especially in patients with cardiovascular risk factors. However, few data are available on the early detection of relationship between arterial stiffness and LV diastolic dysfunction. Methods and Results The common carotid artery intima-media thickness (IMT) and cardio-ankle vascular index (CAVI) were measured to determine the presence of subclinical atherosclerosis in 30 patients (13 men and 17 women; mean age 59 ± 5.7 years) with 1 or more cardiovascular risk factors. LV systolic and diastolic function also were determined by measuring transmitral flow velocity, mitral annular motion velocity, and myocardial strain and strain rate profiles using pulsed Doppler, tissue velocity, and ultrasonic strain imaging. The CAVI correlated with the peak early diastolic velocity of transmitral flow velocity ( r = −0.50, P < .01), the ratio of peak early to late diastolic transmitral flow velocity ( r = −0.37, P < .05), the deceleration time from peak to baseline of the early diastolic transmitral flow velocity ( r = 0.57, P < .01), the peak early diastolic mitral annular motion velocity ( r = −0.41, P < .05), and the peak early diastolic strain rates at the endocardial sites of the LV posterior and inferior walls ( r = 0.61, P < .001; r = 0.56, P < .001, respectively). There were no relationships between CAVI and LV ejection fraction, peak systolic mitral annular motion velocity, or peak systolic strain rates of the LV walls. Multiple regression analysis revealed that the early diastolic strain rates at the endocardial sites of the LV walls are strongly correlated with CAVI. There were no relationships between the IMT and the LV systolic and diastolic parameters. Conclusion These results suggest that cardiovascular risk factors interact to affect arterial stiffness and LV relaxation, and therefore support the importance of screening using CAVI and ultrasonic strain imaging and early intervention in this patient population.

Abstract 2690: Should We Classify Impaired Relaxation Pattern With Elevated E/e’ As Grade 1 Diastolic Dysfunction?

Purpose : Impaired relaxation pattern (grade 1 diastolic dysfunction) by Doppler echocardiography is known to reflect preserved left ventricular filling pressure (LVFP), while increased ratio of early diastolic transmitral flow velocity to mitral annular velocity (E/E’) indicated elevated LVFP. We evaluated the characteristics of impaired relaxation pattern with elevated E/E’ ratio. Methods : Eighty-eight patients (mean age 63 ± 11, 59 males) who had coronary artery disease with impaired relaxation pattern (E/A &lt; 1) were enrolled. Echocardiography including tissue Doppler imaging (TDI) was performed. All patients underwent cardiac catheterization to investigate LV pre-A pressure (LVP pre-A ) within 6 hours after echocardiographic measurement. Patients were divided into subjects with E/E’ &lt; 10 (n = 71) and E/E’ ≥ 10 (n = 17). Results : LVP pre-A was well correlated with echocardiographic Doppler and hemodynamic parameters (E/E’, r = 0.536, p &lt; 0.001; LA volume, r = 0.295, p = 0.008; EF, r = -0.234, p = 0.028). Forty (45% of total) patients had high LVFP, defined as LVP pre-A ≥15 mmHg. Patients with E/E’ ≥10 had a significantly higher incidence of high LVFP, when compared to patients with E/E’ &lt; 10 (88% vs 35%, p &lt; 0.001). LA volume and LVP pre-A were significantly increased and EF was decreased in patients with E/E’ ≥ 10 (table 1 ). However, there were no significant differences of parameters derived from transmitral inflow and transpulmonary venous flow between two groups. Conclusions : In patients with impaired relaxation pattern, elevated E/E’ has related to elevation of LVFP, regardless of transmitral inflow and transpulmonary indices. Therefore, impaired relaxation pattern with elevated ratio of early diastolic transmitral flow velocity to mitral annular velocity (E/E’) may have been considered as another grade of diastolic dysfunction. Table 1

547 Echocardiographic characteristics including tissue Doppler imaging after enhanced external counterpulsation therapy

Background: The aim of this study was to echocardiographically assess the effects of EECP (Enhanced External Counterpulsation Therapy) therapy on systolic and diastolic cardiac function. Methods: LVEF (left ventricular ejection fraction), ESV (end-systolic volume), EDV (end-diastolic volume), Sm (myocardial systolic wave), Ea (myocardial early diastolic wave), Vp (propagation velocity), E/Ea (peak early diastolic transmitral flow velocity/Ea), E/Vp and diastolic function grade were studied in twenty-five patients before and after 35 hours of

Assessment of variables affecting flow propagation velocity of the left ventricle in healthy children

The purpose of the present study was to establish the normal values of flow propagation velocity (FPV) in healthy children and examine the variables that affect FPV in clinical situations. Two hundred and thirty- five healthy children and adolescents were assessed (aged 0-22.6 years, mean age 7.4 +/- 5.4 years; male, n = 142; female, n = 93). FPV was obtained from an apical four-chamber view and determined as the slope of aliasing velocity of early diastolic transmitral flow on the color M-mode using Aloka SSD-5500 with 5.0 MHz transducer. Aliasing velocity was set at 50-70% of the peak transmitral flow velocity. Peak transmitral flow velocities in early diastole (E) and during atrial contraction (A), and the ratio of early to late peak velocity (E/A) were obtained. Tei index was also measured for analysis of general left ventricular performance. Left ventricular mass index (LVMI) was obtained from conventional echo measurement. E, E/A, Tei index and LVMI were compared with FPV in healthy subjects. FPV obtained from all subjects ranged from 23.7 to 96.0 cm/s (61.3 +/- 13.6 cm/s). Normal value of FPV was less dependent on age, body size, heart rate and left ventricular dimension. In contrast, although there was no significant correlation between FPV and ejection fraction, statistically significant correlation was found between FPV, LVMI (P = 0.0008) and Tei index (P = 0.025). FPV is independent of age, body size and heart rate and is useful to assess left ventricular relaxation in children.

Validation of Isovolumic Relaxation Flow Propagation Velocity as an Index of Ventricular Relaxation

To test the applicability of isovolumic relaxation flow propagation velocity (IRFPV) as an indicator of relaxation, 38 patients undergoing cardiac catheterization for chest pain were included. The time constant of isovolumic left ventricular (LV) pressure decline (tau) had a significant correlation with the LV end-diastolic pressure, the peak negative dp/dt, the LV end-diastolic dimension, the fractional shortening, the late diastolic transmitral flow velocity, the early and late diastolic mitral annular velocities, the rapid filling flow propagation velocity, and the natural logarithms of heart rate, ejection fraction, LV end-systolic dimension and IRFPV (r = −0.773, p < 0.001). IRFPV was selected as the major independent determinant of tau, explaining 46% of its variance. In prediction of tau ≥42 ms, the sensitivity and specificity were 100% and 83% for IRFPV ≤104 cm/s, 77% and 67% for the rapid filling flow propagation velocity ≤50 cm/s, and 58% and 67% for the early diastolic mitral annular velocity ≤8 cm/s, respectively. In conclusion, our data suggest that IRFPV could be a better marker of LV relaxation than other parameters, as the rapid filling flow propagation velocity or the early diastolic mitral annular velocity. (E-mail: wcvoon@giga.net.tw)

Long-Term Effects of Atrial Synchronous Ventricular Pacing on Systolic and Diastolic Ventricular Function in Patients with Normal Left Ventricular Ejection Fraction

Background: Atrial synchronous right ventricular pacing (VP) may compromise ventricular function in patients undergoing pacemaker implantation for atrioventricular block. We assessed the usefulness of tissue Doppler imaging (TDI) and color M-mode echocardiography in evaluating patients with VP, and examined the long-term effects of VP on ventricular function by echocardiographic indices and B-type natriuretic peptide (BNP) measurements. Methods: We studied 60 clinically stable elderly dual-chamber pacemaker recipients (mean age: 74 ± 9 years) who had normal left ventricular (LV) systolic function and on the long term the same cardiac rhythm, either intrinsic normal ventricular activation (IA) (n = 20), or VP (n = 40). Results: Paced patients, compared to patients with IA, had decreased stroke volume (p < 0.05) and a more depressed relaxation pattern, as indicated by decreased peak early mitral velocity (E)/peak atrial contraction velocity ratio and tissue Doppler imaging (TDI)-early transmitral diastolic velocity (Ea) measures (p < 0.05). Both groups presented similar BNP levels and LV filling pressures, as assessed by E/Ea and E/early diastolic transmitral flow propagation velocity. In VP patients, age (β = 0.31), Ea (β = –0.28) and E/Ea (β = 0.32) emerged as independent predictors of BNP levels. Conclusions: VP is associated with reduced LV systolic function and signs of impaired relaxation. Elevated BNP levels in elderly VP patients with normal ejection fraction may be predicted by TDI signs of LV diastolic dysfunction.

Angiotensin II Type 1 Receptor Blocker Attenuates Myocardial Remodeling and Preserves Diastolic Function in Diabatic Heart

Blockade of the renin-angiotensin system reduces cardiovascular morbidity and mortality in diabetic patients. Angiotensin II (Ang II) plays an important role in the structural and functional abnormalities of the diabetic heart. We investigated whether or not Ang II type 1 receptor blocker (ARB) could attenuate left ventricular (LV) remodeling in male mice with diabetes mellitus (DM) induced by the injection of streptozotocin (200 mg/kg, i.p.). Diabetic mice were treated with candesartan (1 mg/kg/day; DM+Candesartan, n=7) or vehicle (DM+Vehicle, n=7) for 8 weeks. Heart rate and aortic blood pressure were comparable between the groups. Normal systolic function was preserved in diabetic mice. In contrast, diastolic function was impaired in DM+Vehicle and was improved in DM+Candesartan, as assessed by the deceleration time of the peak velocity of transmitral diastolic flow (40.3+/-0.3 vs. 37.3+/-0.5 ms, p<0.01) and the time needed for relaxation of 50% maximal LV pressure to baseline value (tau; 10.6+/-0.7 vs. 8.7+/-0.6 ms, p<0.05) without significant changes in heart rate and aortic blood pressure. Improvement of LV diastolic function was accompanied by the attenuation of myocyte hypertrophy, interstitial fibrosis and apoptosis in association with the expression of connective tissue growth factor (CTGF) and myocardial oxidative stress. Moreover, candesartan directly inhibited Ang II-mediated induction of CTGF in cultured cardiac fibroblasts. ARB might be beneficial to prevent cardiac abnormalities in DM.

Impact of left atrial appendage exclusion on left atrial function

We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear. Nineteen mongrel dogs (29.7 +/- 5.2 kg) in sinus rhythm were studied. The Doppler signals from the pulmonary venous flow, transmitral flow, and tissue Doppler imaging of mitral annular motion were obtained before and after left atrial appendage exclusion. Dogs were evaluated in the same manner at 7 days (n = 2), 30 days (n = 7), or 90 days (n = 10) after left atrial appendage exclusion. Except for a significant increase in early diastolic transmitral flow velocity after left atrial appendage exclusion (P = .01), no significant differences were found in any parameters related to the transmitral flow and tissue Doppler imaging measurements throughout follow-up. The systolic components of pulmonary venous flow at follow-up revealed a significant reduction relative to baseline (peak systolic velocity P < .0001, systolic velocity-time integral P < .0001), despite the lack of significant changes in left atrial pressure, left ventricular volume, and stroke volume. Left atrial appendage exclusion may affect left atrial reservoir function in the short-term and midterm periods. Further long-term studies with more clinically relevant models are needed.

Both ramipril and telmisartan reverse indices of early diabetic cardiomyopathy: A comparative study

We tested the hypothesis that renin-angiotensin system inhibition could reverse left ventricular diastolic dysfunction in patients with type 2 diabetes. Forty asymptomatic patients with type 2 diabetes were recruited in this double-blind cross-over trial. Left ventricular diastolic function was assessed at baseline with Doppler echocardiography; ratios of early to late peak flow velocity through the mitral orifice (E/A) and velocity time integral of early to late transmitral diastolic flow (VTIE/VTIA) were evaluated. In addition, plasma brain natriuretic peptide (BNP) was measured. Patients received randomly either ramipril (2.5 mg/day), or telmisartan (40 mg/day) or their combination for 3 months. Subsequently, every patient was crossed over to alternative regimens after a 2-week washout period. Measurements were repeated at the end of each treatment period. Both E/A and VTIE/VTIA ratios were increased (29 and 20% with ramipril, 25 and 23% with telmisartan and 36 and 28% with combination treatment, respectively, p < 0.001), whereas plasma BNP levels were significantly reduced with all 3 regimens (9% with ramipril, 25% with telmisartan and 36% with combination, p < 0.001). Both ramipril and telmisartan improve echocardiographic left ventricular diastolic indices and reduce plasma BNP levels in diabetic patients; their combination yields an even better therapeutic effect.

Obesity Cardiomyopathy: Is It a Reality? An Ultrasonic Tissue Characterization Study

Obesity is a well-established risk factor for congestive heart failure. Evidence has been provided indicating that insulin resistance could be the mediator between obesity and congestive heart failure, but the pathogenic mechanisms leading to myocardial alterations remain unclear. The aim of this study was to investigate, by ultrasonic integrated backscatter (IBS) analysis, subclinical alterations of left ventricular (LV) structure and function in severe obesity. Sixty consecutive, severely obese people, who were otherwise healthy (15 men, 45 women; mean age +/- SD = 31.8 +/- 7 years), were enrolled. A total of 48 sex- and age-matched nonobese healthy participants were recruited as control subjects. All participants underwent conventional 2-dimensional color Doppler echocardiography, pulsed wave Doppler tissue imaging at mitral annulus level, and IBS. The homeostasis model assessment insulin resistance index was used to assess insulin resistance; the index values in the obese group were significantly higher (mean +/- SD = 4.9 +/- 1.4) than in the control group (0.92 +/- 0.5, P < .0001). Obese patients had a greater LV mass index by height (58.5 +/- 14 g/m(2.7)) than did control subjects (37 +/- 8 g/m(2.7), P < .0001) because of compensation response to volume overload caused by a greater cardiac output (P < .02). Preload reserve was increased in obese patients, as demonstrated by the significant increase in left atrial dimension (P < .0001). This volumetric increase activated the Frank-Starling mechanism, and determined a significantly higher LV ejection fraction (P < .03) in obese patients as compared with control subjects. A slightly reduced LV diastolic function was demonstrated in obese patients (transmitral early to late peak diastolic transmitral flow velocities ratio = 1.1 +/- 0.7) as compared with control subjects (1.5 +/- 0.5, P < .02). Pulsed wave Doppler tissue imaging showed an impairment of diastolic LV longitudinal function and increased LV diastolic filling pressure. The IBS values at septum level, indexed by pericardium interface, were significantly higher for septum in the obese group (57.8 +/- 8%) than in the control group (42.3 +/- 9%, P < .0001). Additional IBS alterations were observed in the obese group, with a significantly lower cyclic variation index both at septum (P < .0001) and at posterior wall (P < .001) levels. A significant association was found between insulin resistance index and both the IBS index of myocardial reflectivity at septum level (expression of increased myocardial collagen content) or LV mass. In conclusion, this study demonstrates that obese patients exhibit myocardial structural and functional alterations related to insulin resistance and to LV volume overload, which could be considered the very early stage of incipient obesity cardiomyopathy.

Overexpression of glutathione peroxidase attenuates myocardial remodeling and preserves diastolic function in diabetic heart

Oxidative stress plays an important role in the structural and functional abnormalities of diabetic heart. Glutathione peroxidase (GSHPx) is a critical antioxidant enzyme that removes H(2)O(2) in both the cytosol and mitochondia. We hypothesized that the overexpression of GSHPx gene could attenuate left ventricular (LV) remodeling in diabetes mellitus (DM). We induced DM by injection of streptozotocin (160 mg/kg ip) in male GSHPx transgenic mice (TG+DM) and nontransgenic wildtype littermates (WT+DM). GSHPx activity was higher in the hearts of TG mice compared with WT mice, with no significant changes in other antioxidant enzymes. LV thiobarbituric acid-reactive substances measured in TG+DM at 8 wk were significantly lower than those in WT+DM (58 +/- 3 vs. 71 +/- 5 nmol/g, P < 0.05). Heart rate and aortic blood pressure were comparable between groups. Systolic function was preserved normal in WT+DM and TG+DM mice. In contrast, diastolic function was impaired in WT+DM and was improved in TG+DM as assessed by the deceleration time of peak velocity of transmitral diastolic flow and the time needed for relaxation of 50% maximal LV pressure to baseline value (tau; 13.5 +/- 1.2 vs. 8.9 +/- 0.7 ms, P < 0.01). The TG+DM values were comparable with those of WT+Control (tau; 7.8 +/- 0.2 ms). Improvement of LV diastolic function was accompanied by the attenuation of myocyte hypertrophy, interstitial fibrosis, and apoptosis. Overexpression of GSHPx gene ameliorated LV remodeling and diastolic dysfunction in DM. Therapies designed to interfere with oxidative stress might be beneficial to prevent cardiac abnormalities in DM.

Survival Benefits of Different Antiadrenergic Interventions in Pressure Overload Left Ventricular Hypertrophy/Failure

We observed previously that in rats with aortic banding (Bd), development of left ventricular (LV) hypertrophy is opposed by beta-blockade, whereas interventions interfering with alpha-adrenoceptor function also inhibit interstitial fibrosis. To assess whether these differential structural effects do translate into different effects on LV function and on heart failure mortality, Bd or sham Bd 8-week-old rats were randomized to vehicle treatment (Vh), chemical sympathectomy ([Sx] 6-hydroxydopamine, 150 mg/kg IP twice a week), beta-adrenoceptor blockade (propranolol [Pro], 40 mg/kg per day PO), or alpha-adrenoceptor blockade (doxazosin [Dox], 5 mg/kg per day PO). After monitoring survival for 10 weeks, the survivors were anesthetized to undergo echocardiography and intraarterial blood pressure measurement. Bd-Vh rats showed increased LV and lung weights, as well as LV dilation, depressed endocardial and midwall fractional shortening and a restrictive transmitral diastolic flow velocity pattern. Compared with Bd-Vh rats, all of the actively treated Bd rats showed less LV hypertrophy, LV dilation, and lung congestion but no less depression of midwall fractional shortening. In contrast, Sx and Dox but not Pro treatment were also associated with lesser degrees of diastolic dysfunction and, even more importantly, with a striking increase in survival (sham banded rats, 100%; Bd-Vh, 40%; Bd-Pro, 51%; Bd-Sx, 83%; and Bd-Dox, 82%). Although Pro, Sx, and Dox provide similar midterm protection from development of LV hypertrophy and dysfunction and from circulatory congestion, only Sx and Dox favorably affected mortality. These findings indicate that in the aortic banding rat model, alpha-adrenoceptors are importantly involved in the pathogenesis of cardiovascular deterioration and disease progression.

Improved Regional Myocardial Diastolic Function Assessed by Strain Rate Imaging in Patients with Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

This study investigated the effects of percutaneous coronary intervention (PCI) on global and regional left ventricular diastolic function, as assessed by strain rate (SR) imaging. In 27 patients with coronary artery disease, we performed echocardiography before and after PCI to obtain segmental peak systolic SR and peak early diastolic SR (E(SR)). PCI did not significantly change peak systolic SR in the ischemic (1.59 +/- 0.59-1.66 +/- 0.52/s) and nonischemic (1.64 +/- 0.59-1.61 +/- 0.53/s) segments. E(SR) in the ischemic segments was significantly smaller than that in the nonischemic segments at rest (1.82 +/- 0.71 vs 2.03 +/- 0.64/s, P < .01). PCI caused a significant increase in E(SR) from 1.82 +/- 0.71 to 2.29 +/- 0.92/s in the ischemic (P < .001), but not in the nonischemic, segments. The peak early diastolic transmitral flow velocities after PCI were improved in patients with greater extent of improvement of E(SR) in the ischemic segments. These findings suggest that the improvement in left ventricular early diastolic filling after PCI may be associated with the degree of improvement in impaired regional myocardial relaxation.

Clinical features of mixed physiology of constriction and restriction: Echocardiographic characteristics and clinical outcome

An entity of patients with mixed physiology of constriction and restriction has been reported, however, the characteristics of these patients have not been well documented. We evaluated the clinical features and the outcome of these patients. Study subjects consisted of 38 patients (57+/-14 years, 8 females, 30 males) who were diagnosed as having mixed physiology based on transthoracic and/or transesophageal echocardiography, MRI (or CT), cardiac catheterization, endomyocardial biopsy and/or surgical findings. Prior radiation therapy was the most frequent (50%) cause of mixed physiology followed by coronary artery bypass graft without prior radiation (24%) and heart transplantation (8%). The respiratory variation of peak early diastolic transmitral flow velocity by pulsed Doppler transesophageal echocardiography was 10.7% in patients with sinus rhythm and 18.1% in patients with atrial arrhythmia. Pericardial thickening was noted adjacent to the right-sided chambers in 19 patients, left-sided chambers in 10 patients, or both in 9 patients. All-cause 5-year mortality was 40% and unrelated to age, etiology, left ventricular systolic function and therapeutic course. There was a statistically significant difference (p<0.01) between the survival rates in patients with mixed physiology and in patients with pure constriction (n=125). Due to the high mortality in this disease, discrimination of the entity from the patients with pure constriction is mandatory. Transthoracic and transesophageal echocardiography are helpful noninvasive techniques in the diagnosis and the understanding of the physiology of patients with mixed constriction and restriction.

Enhanced Radial Late Systolic Pressure Augmentation in Hypertensive Patients With Left Ventricular Hypertrophy

Wave reflection augments central blood pressure (BP) in late systole, thus increasing cardiac afterload. We examined the relationship between late systolic pressure augmentation in the peripheral radial artery pulse wave and the existence of left ventricular hypertrophy (LVH) in hypertension. Brachial BP, radial augmentation index (AI(r)), and carotid-femoral pulse wave velocity (PWV(cf)) were determined in 77 untreated hypertensive patients aged 56 +/- 10 years. Cardiac structure and function were assessed by ultrasound, and LVH was defined based on the LV mass index (LVMI). Using multivariate analysis, patient characteristics were compared between those with (+) and without (-) LVH. The LVMI was correlated independently and positively with AI(r) (beta = 0.33, P = .004) and the brachial mean arterial pressure (MAP; beta = 0.25, P = .03). The ratio of early to atrial peak velocities (E/A ratio) of the diastolic transmitral flow tended to be correlated negatively with the AI(r). The LVH (+) group had a significantly higher AI(r) than the LVH (-) group [LVH (+), 97% v LVH (-), 89%, P = .003]; this difference remained significant even after adjustment for age, gender, MAP, and heart rate. The adjusted relative risk of LVH was 1.99 for each 10% AI(r) increase (P = .005). In contrast, LVMI was not correlated with the PWV(cf), and the PWV(cf) was not different between the LVH (+) and LVH (-) groups. Moreover, there was no significant correlation between PWV(cf) and AI(r). These results suggest that the peripheral AI(r) measurement is clinically useful in predicting LVH. Enhanced wave reflection may be related to the development of LVH in hypertensive patients.

Diastolic Function in Young Patients with Beta‐Thalassemia Major: An Echocardiographic Study

We aimed to evaluate myocardial diastolic function in patients with beta-thalassemia major (beta-TM) using pulsed-tissue Doppler imaging (TDI) and flow propagation (VP), in relation to BNP levels. We enrolled 192 consecutive patients with beta-TM (88 men (25 +/- 6 years) and 104 women (26 +/- 6 years), with normal left ventricular (LV) systolic function. By TDI, diastolic myocardial velocities were sampled at the lateral section of the mitral annulus (Smv, Emv, Amv). From the apical four-chamber view diastolic transmitral flow velocities, including measures of E- and A-waves were performed. The propagation velocity of early flow into the LV cavity was measured by color M-mode Doppler. Plasma BNP levels were measured in all patients. A nonlinear relationship was found between BNP levels and E/A ratio (beta coefficient for the second-order term = 1.4 +/- 0.4, P = 0.001). We also found a positive association of BNP levels with Amv (r = 0.28, P = 0.023), and a reverse with Smv (r =-0.59, P = 0.01) and Emv/Amv (r =-0.36, P = 0.019). Moreover, an inverse relationship was observed between BNP and Vp (r =-0.43, P = 0.012) levels. Finally, a strong positive linear relationship was found between E/Vp ratio and BNP levels (r = 0.76, P < 0.001). A U-curved association of E/A ratio of transmitral Doppler velocity was revealed with BNP levels, while the tissue Doppler of the Emv/Amv of the mitral annulus movement showed a negative linear association with BNP levels.