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PubMed2001

Mitral regurgitation and left ventricular diastolic dysfunction similarly affect mitral and pulmonary vein flow Doppler parameters: the advantage of end-diastolic markers.

Enhanced early mitral flow and reduced systolic pulmonary vein flow may be caused both by increased left ventricular pressure as the result of diastolic dysfunction and by increased transmitral flow as the result of mitral regurgitation. Nevertheless, Doppler parameters are widely used to predict left ventricular filling pressure. We aimed to analyze the interference of mitral regurgitation with Doppler parameters usually used to estimate left ventricular filling pressure and to identify markers independent of mitral regurgitation, which could reliably estimate increased left ventricular filling pressure. Eighty-four patients (age, 62 +/- 9 years; 82% men) had a complete echocardiographic Doppler examination. Transmitral E- and A-wave velocity, E deceleration time and A duration, pulmonary vein systolic and diastolic velocities, and reversal flow duration and maximal and minimal left atrial volumes were measured. The difference between the duration of pulmonary vein and mitral A waves was calculated (A'-A). Mitral regurgitant volume was quantitatively assessed by echocardiography. Left ventricular end-diastolic pressure was measured invasively. Patients had a wide range of left ventricular ejection fraction (14% to 70%), mitral regurgitant volume (0 to 94 mL), and left ventricular end-diastolic pressure (3 to 37 mm Hg). E velocity, E/A, pulmonary vein systolic and diastolic, and systo-diastolic ratios were significantly and independently correlated with both left ventricular end-diastolic pressure and mitral regurgitant volume. A'-A showed a strong correlation with left ventricular end-diastolic pressure (r = 0.70; P <.0001), but the relation with mitral regurgitant volume was not significant (r = 0.19; P =.08). Mitral regurgitation affects the majority of Doppler parameters widely used to predict filling pressure but does not influence Ad'-Ad, which proved to be the strongest predictor of left ventricular end-diastolic pressure.

Aged↗
PubMed2000

Diastolic dysfunction as a cause of exercise intolerance.

Tachycardia accompanying exercise shortens the duration of diastole, reducing the time available for the left ventricular (LV) filling. Thus, the LV must fill more rapidly for the stroke volume to increase (or even be maintained) during exercise. Normally, this is accomplished without requiring an excessive increase in left atrial (LA) pressure by an acceleration of LV relaxation and a fall in LV early diastolic pressure during exercise. This response is lost following the development of heart failure due to systolic dysfunction, both in experimental animals and in patients. In fact, in such situations, LV relaxation slows and LV early diastolic pressure increases due to exercise. Thus, any diastolic dysfunction present at rest in CHF during systolic dysfunction is exacerbated during exercise. Similarly, patients with primary diastolic dysfunction heart failure with preserved systolic function may not be able to augment LV filling rates without an abnormal increase in LA pressure. Thus, diastolic dysfunction may contribute to exercise intolerance, both in systolic dysfunction and primary diastolic dysfunction. Acute studies suggest that treatment with angiotensin II receptor blockers or verapamil may improve exercise tolerance in some patients with primary diastolic dysfunction.

Animals↗
PubMed1992

Effects of progressive myocardial ischaemia on systolic function, diastolic dysfunction, and load dependent relaxation.

OBJECTIVE: The aims were to determine (1) the relationship between changes in contractile function (systolic shortening) and the appearance of diastolic dysfunction (postsystolic shortening) during progressive regional left ventricular ischaemia; (2) the effects of increased afterload (acute constriction of the descending thoracic aorta) on ischaemic contractile dysfunction; and (3) the effects of loading during ischaemia on load dependent relaxation. METHODS: Regional myocardial function, using sonomicrometry, was measured in the short and long axes of the apex of the left ventricle of eight open chest anaesthetised dogs (16-20 kg). Progressive apical ischaemia was induced by graded reductions in left anterior descending coronary artery flow (critical constriction, ischaemia 1, ischaemia 2, total coronary occlusion, and postocclusive maximum reactive hyperaemia). Acute afterloading was induced by a snare placed around the descending aorta. RESULTS: Consistent decreases in systolic shortening and increases in postsystolic shortening relative to the total segmental shortening in the short axis of the apical region were seen with worsening ischaemia. Aortic constriction increased the magnitude of apical postsystolic shortening and decreased apical systolic shortening in the short axis during critical constriction, ischaemia 1, and ischaemia 2. Long axis function changed in a qualitatively similar but quantitatively different manner. There was a significant decrease in the load dependency of relaxation with total coronary occlusion. CONCLUSIONS: (1) Changes in systolic and diastolic function occurred concomitantly as mild regional myocardial ischaemia developed and intensified; (2) afterloading significantly worsened regional systolic and diastolic dysfunction during mild ischaemia; and (3) progression of regional ischaemia resulted in loss of load dependent relaxation.

Animals↗
PubMed2002

Elevated serum uric acid levels are associated with diastolic dysfunction in patients with dilated cardiomyopathy.

OBJECTIVE: To assess whether serum uric acid, which is a marker of impaired oxidative metabolism, might correlate with left ventricular systolic and diastolic dysfunction in patients with chronic heart failure (CHF). BACKGROUND: Uric acid levels, which are frequently elevated in patients with CHF, correlate with leg vascular resistance. The effects of elevated levels of uric acid on cardiac function in patients with CHF have never been evaluated. METHODS: We studied 150 outpatients with CHF who came to our heart failure clinic. Patients underwent a complete echo-Doppler examination, with measurement of mitral E wave and mitral A wave velocities, E/A ratio, E wave deceleration time (DtE), left ventricular volumes, ejection fraction, and stroke volume. A restrictive mitral filling pattern (RMFP) was defined as either E/A ratio >2 or E/A >1 and DtE <140 milliseconds. RESULTS: Mean age was 62.2 +/- 7.8 years (86% male); 24 patients (16%) had an RMFP. Patients with an RMFP had significantly higher uric acid levels compared with patients without RMFP (0.48 +/- 0.14 mmol/L vs 0.38 +/- 0.08 mmol/L, respectively, P <.001). Uric acid levels correlated significantly with mitral E wave velocity (r =.22, P <.01), E/A ratio (r =.21, P <.05), DtE (r =.26, P <.01), and RMFP (P =.0001). There was no correlation between uric acid and left ventricular volumes, ejection fraction, or stroke volume. In a multivariate model, uric acid predicted DtE independently of renal function, diuretic dose, and left ventricular volumes. CONCLUSION: Elevated uric acid levels are associated with diastolic dysfunction in CHF. Xanthine oxydase inhibition in patients with CHF might theoretically result in an improvement of diastolic function.

Aged↗
PubMed1998

Treatment of diastolic dysfunction in hypertensive patients without left ventricular hypertrophy.

The aim of this study was to evaluate the influence of verapamil SR 240 mg (V) and the combination amiloride 5 mg + hydrochlorothiazide 50 mg (AH) on diastolic dysfunction of hypertensive patients without left ventricular hypertrophy (LVH). Twenty-six hypertensive patients with diastolic dysfunction, normal systolic function and without LVH were included into a 2-week washout period and then randomised to a 6-month V or AH treatment. One blinded-to-treatment echocardiographist at baseline and at weeks 4, 12 and 24 assessed Doppler-echocardiography. Both V and AH, satisfactorily controlled blood pressure, but only V improved diastolic function shown by a tendency to reduce peak A and to increase peak E/A ratio, and by a significant reduction in deceleration time. After 24 weeks, V significantly reduced wall thickness in comparison with AH. These results need to be confirmed in a larger scale study.

Adult↗
PubMed1990

[Early diastolic dysfunction of the left ventricle affected by hypertrophy and abnormal histopathology in hypertrophic cardiomyopathy].

In this study, we investigated correlations of left ventricular hypertrophy and its histopathology with diastolic dysfunction in patients with hypertrophic cardiomyopathy. Nine control subjects and 14 hypertrophic cardiomyopathy (HCM) patients with asymmetrical septal hypertrophy were evaluated. M-mode echocardiography was used to assess fractional shortening (FS), isovolumic relaxation time (IRT), and the left ventricular filling volume index during rapid and slow filling periods and atrial contraction period (RFVI, SFVI and ACVI). End-diastolic thickness of the interventricular septum and posterior wall was determined using biventriculography. Right ventricular endomyocardial biopsies were performed to calculate the diameters of myocytes, the percentage of fibrosis and the eccentricity e which indicates the degree of myocardial disarrangement including disorganization. The FS was normal in the two groups. The IRT of the HCM group was significantly greater and the RFVI significantly less than those of the controls. The left ventricular wall thickness, the diameters of myocytes and the percentage of fibrosis in the HCM group were significantly greater; and the eccentricity e was significantly less, suggesting that myocardial disarrangement was significantly more severe than that in the controls. Significant positive correlations were observed between the IRT and the wall thickness (r = 0.647), between the diameter of myocytes (r = 0.681) and the percentage of fibrosis (r = 0.628), and there was a significantly negative correlation between the IRT and the eccentricity e (r = -0.759). There was a significantly negative correlation between the RFVI and the wall thickness (r = -0.663); and a significantly positive correlation between the RFVI and the eccentricity e (r = 0.579). Multiple regression analyses showed that the diameter of myocytes, the percentage of fibrosis and the eccentricity e all correlated significantly with the IRT (R = 0.821) and the RFVI (R =0.604). The standard regression coefficients of the diameter of myocytes, the percentage of fibrosis and the eccentricity e were 0.253, 0.278 and -0.431 in respect to IRT, and those of the percentage of fibrosis and the eccentricity e were -0.204 and 0.469 in respect to RFVI, respectively. These results indicated that diastolic dysfunction in hypertrophic cardiomyopathy is related not only to the degree of left ventricular hypertrophy, but also to the degree of myocardial hypertrophy, increased interstitial fibrosis, and especially to myocardial disarrangement including disorganization.

Adult↗
PubMedDate not supplied

[Diastolic dysfunction as a cause of heart failure in the hypertensive patient].

Hypertensive cardiomyopathies can be divided into 4 ascending categories according to the pathophysiologic and clinical impact of hypertension on the heart: Grade I. This category is characterized by LV diastolic dysfunction with no associated LV hypertrophy. Grade II. Patients at this stage present LV diastolic dysfunction with echocardiographic LV hypertrophy. Exercise capacity in terms of maximal oxygen consumption may be normal (Grade IIA) o impaired (Grade IIB). Grade III. This stage is distinguished by the presence of congestive heart failure (severe dyspnea and X-ray pulmonary edema with normal EF (> or = 50%). Patients having LV mass/volume ratio > 1.8 with little or no myocardial ischemia are classified as IIIA, as compared with IIIB patients having LV mass/volume ratio < 1.8 and significant myocardial ischemia. Clinically, these two subgroups can be distinguished as follows: the presence of a fourth sound and the absence of cardiomegaly for classification as IIIA, and a third sound plus cardiomegaly for classification as IIIB. Grade IV. Here the profile is one of dilated cardiomyopathy, LV hypertrophy and impaired EF (< 50%). The 5-year mortality rate is higher for Grade IV patients than for Grade III patients, although the morbility rate is similar in both.

Adult↗
PubMed2001

Microalbuminuria as a marker of preclinical diastolic dysfunction in never-treated essential hypertensives.

Using 24-h ambulatory blood pressure (BP) monitoring and digitized M-mode echocardiography, we evaluated whether microalbuminuria is related to preclinical left ventricular (LV) diastolic dysfunction in hypertensive patients. We selected 87 never-treated hypertensive patients (mean 24-h BP > 140 and/or > 90 mm Hg); albuminuria was evaluated as mean value of 24-h urinary albumin excretion (UAE) from two 24-h urine collections. Microalbuminuria was found in 28 patients, classified as MA+ (UAE 30 to 300 mg/24 h); 59 patients had normal UAE (< 30 mg/24 h) and were classified as MA-. The MA+ and MA- groups did not differ with regard to age, sex, body mass index, or 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic BP were significantly higher in MA+ than in MA-. The LV mass index was greater in MA+, as was the prevalence of LV hypertrophy; peak shortening rate of LV diameter, index of systolic function, was normal in all, but was lower in MA+. Peak lengthening rate of LV diameter and peak thinning rate of posterior wall, indices of diastolic function, were lower in MA+ and the prevalence of diastolic dysfunction was higher in MA+. UAE was inversely correlated with both indices of LV diastolic function, also after correction for age, 24-h heart rate, 24-h BP, and LV mass. In conclusion, in never-treated hypertensive patients, microalbuminuria is not only associated with greater myocardial mass, but is also related with preclinical impairment of LV diastolic function. This relation, independent from increased BP or LV mass, strengthens the role of microalbuminuria as an early and reliable marker of preclinical cardiac involvement.

Adult↗
PubMed1992

Noninvasive detection of left ventricular diastolic dysfunction using M-mode echocardiography to assess left ventricular posterior wall kinetics in hypertrophic cardiomyopathy.

In patients with hypertrophic cardiomyopathy (HC), it is difficult to determine the severity of left ventricular (LV) diastolic dysfunction. Three different patterns of LV posterior wall motion were found by M-mode echocardiography in patients with HC, and the use of these patterns is proposed as a new noninvasive index of the severity of LV diastolic dysfunction. M-mode echocardiograms were recorded prospectively from 35 patients with HC, and the posterior wall motion pattern in late systole and early diastole was classified into the following 3 types: (1) normal motion (n = 9); (2) flat motion--flat motion from late systole to early diastole, followed by rapid backward movement (n = 13); and (3) downward motion--slow backward movement from late systole (n = 13). There were no differences in the severity or type of hypertrophy, LV systolic function and pulsed Doppler indexes of LV filling among these 3 groups. However, LV end-diastolic pressure was increased in the groups with flat (15 +/- 6 mm Hg) and downward (16 +/- 9 mm Hg) motion. Furthermore, the maximal rate of decrease in LV pressure (normal 1,450 +/- 300, flat 1,250 +/- 300 and downward 860 +/- 80 mm Hg/s) and the time constant of LV pressure reduction (normal 60 +/- 15, flat 70 +/- 25 and downward 101 +/- 34 ms) showed a stepwise deterioration from the normal to the flat and then to the downward motion groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMedDate not supplied

[Diastolic dysfunction in patients with chronic kidney failure on a hemodialysis program].

OBJECTIVE: The aim of this study was to analyse different ultrasound parameters for the assessment of isolated left ventricular diastolic dysfunction (LVDD) in patients with chronic renal failure (CRF) on periodic hemodialysis (HD), comparing pulsed wave Doppler with pulsed tissue Doppler. MATERIALS AND METHODS: Forty-seven patients with CRF on HD (61% were male; mean age was 51.0 +/- 16.5 years, mean HD time--3.7 +/- 3.8 years, 38% had hypertension, 17% had diabetes) were studied by echocardiography (bidimensional, M-Mode, flow pulsed Doppler and tissue Doppler imaging). All patients had symptoms of left heart failure-class II NYHA, were in sinus rhythm and had no symptoms of ischemic heart disease. The presence of abnormal LV regional contractility was the exclusion criteria. According to their mitral inflow profile Doppler characteristics, patients were included in two groups: Group A (E/A > 1; n = 21) and B (E/A < 1; n = 26). We compared: LV dimensions and function, left atrial (LA) dimension. Gaasch index, LV mass index. E and A wave velocities (in flow pulsatile Doppler and tissue Doppler). E/N ratio in tissue Doppler, isovolumetric relaxation time (IVRT) and deceleration time (DT). RESULTS: There were no significant differences in the prevalence of age > or = 65 years male sex, hypertension or diabetes between group A and B patients, and almost all patients were on hemodialytic treatment for more than one year (81% vs 85%: NS). LV hypertrophy was present in almost all group A and B patients (A--95% vs B--85.5%; NS). Group A, compared with group B, had a difference in the Gaasch index (2.45 +/- 0.3 vs 2.08 +/- 0.4; p < 0.05), E wave velocity in flow pulsatile Doppler and tissue Doppler (cm/sec) (110 +/- 27 vs 62 +/- 20; p < 0.001 and 41 +/- 15 vs 28.5 +/- 16; p < 0.05), E/A ratio in tissue Doppler (1.3 +/- 0.4 vs 0.8 +/- 0.3; p < 0.001). IVRT (msec) (80.7 +/- 15.2 vs 113.5 +/- 28.3; p < 0.001) and DT (msec) (189.7 +/- 24 vs 278.2 +/- 17.9; p < 0.001). According to the E'/A' ratio in tissue Doppler, group A patients were divided in another two groups: E'/A' > 1 (13/21--62%) and < 1 (8/21--38%) and a significantly longer IVRT (75.8 +/- 9.3 vs 100.9 +/- 3.2; p < 0.001) and DT (178 +/- 15 vs 240 +/- 20; p < 0.001) and a greater LA dimension (37.6 +/- 6.9 vs 44.6 +/- 6.9; p < 0.05) were found. CONCLUSIONS: Pulsed wave Doppler is the most useful non invasive method for assessment of global diastolic dysfunction. In our study, 17% of the patients had E/A < 1 only in the tissue Doppler study. These patients probably had a pseudonormal mitral pattern.

Adult↗
PubMed2001

Impact of myocardial diastolic dysfunction on coronary flow reserve in hypertensive patients with left ventricular hypertrophy.

BACKGROUND: The aim of the study was to assess the possible association, in hypertensive patients, between left ventricular myocardial diastolic dysfunction and coronary flow reserve (CFR) in relation to the presence of left ventricular hypertrophy (LVH). METHODS: Twenty-eight untreated hypertensives (22 males, 6 females, mean age 53.1 years), free of coronary artery disease, were enrolled in the study. Standard Doppler echocardiography, color Doppler tissue imaging of the posterior septum during dobutamine stress and second harmonic Doppler of the distal left anterior descending coronary vessel, at baseline and after maximal hyperemia induced by dipyridamole, were performed. CFR was estimated as the ratio between hyperemic and baseline diastolic velocities. Hypertensives were divided into two groups according to the left ventricular mass index: 15 without LVH (left ventricular mass index < 51 g/m2.7) and 13 with LVH (left ventricular mass index > 51 g/m2.7). The two groups were comparable for sex prevalence, age, body mass index, baseline heart rate and blood pressure. RESULTS: Color Doppler tissue imaging did not show any significant difference of both the baseline and high-dobutamine septal systolic peak velocities between the two groups. The ratio between myocardial early and atrial peak velocities (Em/Am ratio) was lower in patients with LVH, either at baseline (p < 0.01) or at high-dose dobutamine (p < 0.0001). Also, CFR was lower in the presence of LVH (p < 0.01). After adjusting for age, body mass index, left ventricular mass index, diastolic blood pressure and high-dose dobutamine heart rate by a multiple linear regression analysis, the high-dose dobutamine Em/Am ratio was an independent contributor of CFR in the overall hypertensive population (beta = 0.65, p < 0.0001) (cumulative r2 = 0.38, p < 0.0001). CONCLUSIONS: The combined use of second harmonic Doppler and color Doppler tissue imaging identifies, in arterial hypertension, an association between myocardial diastolic properties and CFR, independent of the presence of LVH. In hypertensive patients free of coronary artery stenosis, left ventricular myocardial diastolic dysfunction may be a determinant in the impairment of the coronary microvessel vasodilation capacity or a marker of silent ischemia involving the microvascular circulation.

Blood Flow Velocity↗
PubMed2001

Diastolic dysfunction is predictive of difficult weaning from cardiopulmonary bypass.

Diastolic function is receiving more attention since echocardiographic measurements were developed and have become widely available. The importance and significance of diastolic dysfunction (DD) observed before cardiac surgery and its relationship with adverse outcomes, such as difficult separation from cardiopulmonary bypass (CPB), have not been fully explored. In this study, we hypothesize that DD can be a predictor for the need of inotropic support to successfully separate from CPB. Ninety-two consecutive patients underwent surgery during the study period. Twenty-six patients were excluded. From the remaining 66 patients, 52 had coronary artery bypass grafting alone and 14 combined procedures, valvular surgery, and reoperations (redo). Systolic and diastolic function was evaluated by two experts blinded as to the clinical data except for the age. The evaluation of diastolic function was done according to published guidelines. The demographic, echocardiographic, and hemodynamic variables were entered in a logistic regression analysis to determine which variables were independent predictors of difficult separation from CPB and the need for postoperative vasoactive support. DD was present in 20 patients (30%). Patients with DD had lower weight (P = 0.046), less frequent coronary artery bypass grafting alone (P = 0.0004), more myocardial infarction before surgery (P = 0.02), higher regional wall motion score index (P = 0.0002), and larger left ventricle (P = 0.03). Total CPB time (P = 0.004) and ischemic time (P = 0.007) were longer in the DD group. Patients with DD required more frequent inotropic support at the end of surgery (P = 0.006) and up to 12 h after surgery (P = 0.003). Multivariate logistic regression identified female sex, DD, and total CPB time as predictive of difficult weaning and inotropic requirements up to 12 h after surgery.

Aged↗
PubMed1994

Recovery of load-induced left ventricular diastolic dysfunction by coenzyme Q10: echocardiographic study.

UNLABELLED: Load-induced cardiac dysfunction (LCD), in which a supernormal left ventricular (LV) systolic performance at rest decreases due to an afterload challenge, usually occurs among children with mitral valve prolapse (MVP). However, diastolic performance is also important because relaxation, like contraction, is based on a process that requires energy. The aim of this study was to examine LV diastolic response patterns to stress in patients with LCD before and after coenzyme Q10 (CoQ) therapy and in controls. The D-E slope, E-F slope and maximal diastolic endocardial velocity were used as echographic diastolic indices. Thirty subjects, aged 9-16 years, were divided into four groups: group 1, 10 normals; group 2, 10 patients with LCD; group 3, the same 10 as in group 2, who recovered with CoQ, 3.0-3.4 mg/kg/day for 7 days; group 4, 10 asymptomatic children with MVP. The heart rate, both at rest and during handgrip (HG), showed little intergroup difference. Only in group 2, were the ejection fraction and all the diastolic indices greater than in the other groups, but these became subnormal with HG. In the other groups, these indices increased with HG to a similar extent, although resting values were smaller than in group 2. IN CONCLUSION: (1) in normal hearts and in hearts with LCD, diastolic performance mimicked systolic performance both in resting and loading conditions; (2) CoQ improved not only the load-induced systolic but also the diastolic dysfunctions in a similar time-course, and (3) mechanical stiffness of the cardiac tissue may not be a cause of load-induced diastolic dysfunction, because the dysfunction was quickly resolved with CoQ therapy. CoQ may be a key substance which affects a common bioenergetic process in contraction and relaxation, to keep these functions normal.

Adolescent↗
PubMed1998

Pharmacological strategies for improving diastolic dysfunction in the setting of chronic pulmonary hypertension.

BACKGROUND: Right ventricular (RV) hypertrophy is an adaptive process that occurs in the setting of chronic pulmonary hypertension (CPH) and can lead to alterations in normal RV diastolic properties. This study was designed to investigate the effects of NO and milrinone on RV diastolic dysfunction in the setting of CPH and RV hypertrophy by use of a canine model of monocrotaline pyrrole (MCTP)-induced CPH. METHODS AND RESULTS: Sixteen mongrel dogs (22 to 24 kg) were used. Animals underwent percutaneous pulmonary artery (PA) catheterization to measure pulmonary hemodynamics before and 8 weeks after injection of 3 mg/kg MCTP (n=8) or placebo (control, n=8). Eight weeks after injection, all hearts were instrumented with a PA flow probe, sonomicrometric dimension transducers, and micromanometers. Data were collected at baseline and after both NO and milrinone administration. Diastolic properties were quantified by use of the end-diastolic pressure-volume relationship and the time constant of ventricular isovolumic relaxation. Eight weeks after injection, significant increases in the PA pressure and pulmonary vascular resistance were observed in MCTP dogs. Significant worsening of RV diastolic function occurred in association with significant increases in the ratio of RV dry weight to LV+septal dry weight. NO and milrinone administration both led to significant improvements in RV diastolic properties. CONCLUSIONS: In the setting of MCTP-induced CPH, significant worsening of RV diastolic function was observed in association with significant increases in the ratio of RV dry weight to LV+septal dry weight, suggesting that these changes are partially due to RV hypertrophy. The significant improvement in RV diastolic properties after both NO and milrinone administration suggests that these agents may be effective forms of pharmacological therapy for improving RV diastolic dysfunction in the setting of CPH.

Administration, Inhalation↗
PubMed1988

Enhanced sensitivity to hypoxia-induced diastolic dysfunction in pressure-overload left ventricular hypertrophy in the rat: role of high-energy phosphate depletion.

Isolated buffer-perfused rat hearts with pressure-overload hypertrophy develop a greater decrease in left ventricular (LV) diastolic distensibility and a greater impairment in extent of LV relaxation in response to hypoxia than do normal hearts. Using 31P-NMR spectroscopy, we tested the hypothesis that the enhanced susceptibility of hypertrophied hearts to develop hypoxia-induced diastolic dysfunction is due to an accelerated rate of ATP and/or creatine phosphate depletion. Twelve minutes of hypoxia were imposed on isolated isovolumic (balloon-in-left-ventricle) buffer-perfused hearts from 14 rats with pressure-overload hypertrophy (LVH; LV/body wt ratio = 3.43 +/- 17) secondary to hypertension induced by uninephrectomy plus deoxycorticosterone and salt treatment and from 17 age-matched controls (LV/body wt ratio = 2.22 +/- 0.12, p less than 0.001). Coronary artery flow per gram left ventricle was matched in the LVH and control groups during baseline oxygenated conditions and held constant thereafter. Balloon volume was held constant throughout the experiment so that an increase in LV end-diastolic pressure during hypoxia represented a decrease in LV diastolic distensibility. LV systolic pressure was 165 +/- 9 mm Hg in the LVH group compared with 120 +/- 5 mm Hg in the controls during baseline aerobic perfusion (p less than 0.001). LV end-diastolic pressure rose significantly more in response to 12 minutes of hypoxia in the LVH group (12 +/- 1 to 44 +/- 10 mm Hg) than in the controls (12 +/- 1 to 20 +/- 3 mm Hg, p = 0.04). During baseline aerobic conditions, ATP content was the same in the LVH (17.1 +/- 0.5 mumol/g dry LV wt, n = 4) and control (18.8 +/- 0.6 mumol/g dry LV wt, n = 4, p = NS) groups. During hypoxia, ATP declined at the same rate in the LVH and control groups (3.2 +/- 0.5 versus 3.0 +/- 0.5%/min, p = NS) despite the greater rise in end-diastolic pressure in the LVH group. Creatine phosphate content during baseline aerobic perfusion was 14% lower in the LVH group compared with controls, but the rate of creatine phosphate depletion during 12 minutes of hypoxia was the same. During hypoxia, intracellular pH declined modestly and to the same degree in both groups. Thus, the greater susceptibility to hypoxia-induced diastolic dysfunction observed in isolated buffer-perfused hypertrophied rat hearts cannot be explained by an initially lower total ATP content or by an accelerated rate of decline of ATP or creatine phosphate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗
PubMed1997

[Diastolic dysfunction of the left ventricle: from physiopathology to treatment].

Our understanding of cardiac failure has greatly changed over the last 15 years. Left ventricular diastolic dysfunction, which is now recognised as one of the primary causes of certain types of cardiac failure (1). Abnormal left ventricular diastolic function is the common determinant and indeed the earliest sign of all chronic left ventricular failures whether systolic left ventricular dysfunction is associated with it or not (2). In this paper, we review the basis of diastolic dysfunction and its impact on diagnosis and treatment of cardiac failure.

Aged↗
PubMed1998

[Value of echocardiography and heart Doppler in the diagnosis and therapeutic orientation of congestive heart failure--the importance of diastolic dysfunction].

Echocardiography and cardiac-Doppler are very useful techniques to achieve etiologic diagnosis and evaluate therapeutic strategies for heart failure, and left ventricular hypertrophy is known as a serious risk factor for cardiovascular disease morbidity and mortality. Echocardiography establishes, in an easy and noninvasive way, the etiologic diagnosis of heart failure and is a very sensitive technique for the diagnosis and follow-up of patients with left ventricular hypertrophy. On the other hand, diastolic dysfunction is an early manifestation of several conditions associated with heart failure emerging from the diastolic mechanism. The author emphasizes the role of cardiac Doppler in the early diagnosis of diastolic dysfunction and how findings provided by this procedure can lead to more adequate therapeutic measures and assess accurate prognostic information.

Diastole↗
PubMed2000

Diastolic dysfunction in the elderly. Genesis and diagnostic and therapeutic implications.

Diastolic left ventricular function is altered substantially with advancing age in healthy persons, and diastolic dysfunction impacts most cardiovascular disorders in the elderly. Older, healthy persons have a delayed relaxation Doppler filling pattern and their early deceleration time is similar to, or modestly lengthened, compared with younger, healthy persons. Two abnormal Doppler filling patterns, the pseudo-normal and the restricted, are discerned more easily, and are more specific in the elderly than the young, because they are the opposite (reverse) of the normal elderly pattern. Most heart failure in the elderly occurs in the presence of preserved systolic function (presumed diastolic heart failure). Elderly patients with diastolic heart failure tend to be women with hypertrophied, hyperdynamic left ventricles, and chronic hypertension. Prognosis may be somewhat better than in systolic heart failure, but the difference diminishes when adjusted for gender and in the very elderly. The pathophysiology of this disorder is not well characterized, diagnostic criteria have not been standardized, and there are no large, multicenter, randomized trials to guide therapy. Further research in this area should be a high priority.

Aged↗