Subnormal Ejection Fraction Research Articles

P1421 Patients with severe aortic regurgitation showed systolic dysfunction and increased stroke work despite preserved EF; clues for reconsidering optimal time point of surgery

Abstract Background Current guidelines recommend surgery in patients with severe aortic regurgitation (AR) with clinical symptoms or subnormal ejection fraction (EF). Furthermore, surgery should be considered in patients with severe AR, preserved EF and increased left ventricular diameters (LVEDD >70mm, LVESD >50mm). The aim of the study was to investigate LV systolic function as well as mechanical energetics using non-invasive pressure-volume- and strain analysis in patients with severe AR and preserved EF as well as moderately dilated ventricles (LVEDD <70mm). Methods and Results Echocardiographic strain and single beat pressure-volume analyses were performed in patients with severe AR and moderately increased ventricular size (LVEDD < 70mm, EF >50% n = 39) as well as healthy, age-matched controls (n = 20) using echo-derived volume and arm-cuff blood pressure measurements. Load independent parameters of systolic contractile function like end-systolic elastance (Ees) and end-systolic volume at 100mmHg (ESV100) were calculated as well as stroke work ((SW) and total pressure volume area (PVA = SW + potential energy). Patients with AR demonstrated significant depression of systolic function beyond ejection fraction: global longitudinal strain was reduced compared to controls (-16 ±2.5% vs. -21.5 ±2%; p < 0.001). Accordingly load independent parameters of LV contractility like Ees (1.5mmHg/ml ±0.7 vs. 2.25mmHg/ml ±0.7; p < 0.001), ESV100 (65.7ml ±19.4 vs. 42.4ml ±19.8; p < 0.05) were reduced despite comparable ejection fractions (EF: 0.56% ±0.05 vs. 0.60% ±0.07 p = 0,10). End-diastolic volume of AR patients was markedly elevated (236ml ±90 vs. 136ml ±30; p < 0.001), while PVA (20470mmHg x ml ±10400 vs. 11907mmHg x ml ±2877; p < 0.01) and stroke work (13200mmHg x ml ±5700 vs. 7606 mmHG x ml ±2048; p< 0.01) were markedly elevated indicating waste of energy. Conclusion Patients with severe AR and moderately enhanced LV showed depressed values of contractility and waste of energy using more advanced parameters of LV systolic function although EF was preserved. The data may demonstrate that surgery is performed too late in many of those patients and may give clues for reconsidering guidelines to meet the optimal time point of surgery. .

Ambulatory venous pressure, air plethysmography, and the role of calf venous pump in chronic venous disease

BackgroundAmbulatory venous pressure (AMVP) records pressure dynamics with calf exercise. Air plethysmography (APG) measures related volume detail. APG has been suggested as a noninvasive surrogate for AMVP. We examine the correlations between APG and AMVP parameters and the role of “calf pump failure” in chronic venous disease (CVD). MethodsA total of 8456 limbs in 4610 patients investigated for CVD during a 20-year period were analyzed. APG and AMVP data were available in 4599 limbs for calculation of Pearson correlation coefficient; 1347 of these limbs had significant iliac vein stenosis, proven by intravascular ultrasound. Venn diagrams are used to explore overlapping incidence of APG and AMVP abnormalities. ResultsAPG calf volume and reflux (venous volume, venous filling index) showed progressively significant deterioration with advancing Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) clinical class, anatomic extent of reflux (superficial, deep, perforator), and reflux severity (axial reflux, segmental score). Notably, calf ejection volume increased in a nearly linear fashion (R = 0.71) to venous volume such that residual volume fraction (RVF) remained normal even in the worst of these categories. AMVP too progressively deteriorated with clinical disease and reflux severity. Venous filling time was the key parameter as the pressure drop alone was abnormal in only 4% of the limbs analyzed. There was no correlation between RVF and AMVP (R = 0.22) or between AMVP and many other APG parameters. Venn distribution showed only minor overlap (30%) between AMVP and key APG abnormalities overall, but the overlap increases from 40% to 70% in advanced clinical and reflux categories. AMVP was rarely abnormal (7%) when APG was normal. Median AMVP was normal in calf pump failure categories, however defined (subnormal ejection fraction, RVF, or both). Median AMVP is normal in venous obstruction without reflux, while AMVP abnormalities are associated three to seven times more with reflux than with obstruction. ConclusionsAPG (venous filling index) is a useful index of reflux. Calf pump ejection is a powerful and plastic compensatory mechanism, and calf pump failure is rare. Ambulatory venous hypertension is dominantly associated with reflux and less with obstruction. AMVP too worsens with clinical and reflux severity categories. However, there is little correlation between APG and AMVP parameters as APG measures volume and AMVP measures pressure, each in its own domain, and the volume-pressure curve is nonlinear. AMVP may be omitted in routine clinical testing if APG is normal, as the yield (7%) will be very low. AMVP reflects venous hypertension, the end stage in CVD. AMVP should be used to identify such cases when APG is abnormal.

Tissue Doppler and myocardial deformation imaging to detect myocardial dysfunction in pediatric cancer patients treated with high doses of anthracyclines

To detect subtle changes in myocardial function in pediatric cancer patients treated with high dose anthracyclines. In all, 19 pediatric cancer patients with no cardiotoxicity findings treated with a cumulative anthracycline dose of ≥350 mg/m(2) and healthy participants of the same age were included in the study. Transthoracic echocardiography measurements, pulsed-wave tissue Doppler from the basal portions of all walls and strain and strain rate imaging of all walls from basal portion were obtained. A total of 19 patients (13 boys and six girls) and 17 participants (10 boys and seven girls) in the control group were enrolled. Three patients had subnormal ejection fraction (EF) and fractional shortening (FS) values. There was no significant difference in EF and FS between the two groups. The left ventricle isovolumic relaxation time was prolonged (P = 0.02) and the mitral color propagation velocity was decreased in patients (P = 0.001). Peak systolic strain and strain rates of the right ventricle, septal, lateral and inferior wall basal region of the left ventricle were significantly lower in patients than controls (all P < 0.05). Tissue Doppler measurements of early and late diastolic myocardial velocities of the right ventricular free wall, lateral wall of left ventricle and septum, and peak systolic myocardial velocity of the left ventricle anterior wall were significantly lower in patients (all P < 0.05). Myocardial Doppler and deformation imaging techniques provide a thorough evaluation of cardiac functions with the advantage of detecting subtle early changes before a global cardiac functional impairment occurs.

Inter- and intra-study reproducibility of contrast echocardiography for assessment of interventricular septal wall perfusion rate in humans.

To assess inter- and intra-study reproducibility of myocardial contrast echocardiography (MCE) imaging for quantitative measurement of myocardial perfusion rate in humans in ambulatory setting. In 20 subjects, we performed 2 MCE tests 20-40 min apart on the same day under the same standardized protocol, and evaluated single-reader between-study and between-reading reproducibility of assessment of indicators of myocardial perfusion rate, such as the slope of video-intensity change k, and the factors A (peak video-intensity) and B (background video-intensity after bubble destruction) and the product k X A. The region of interest was placed at the mid-posterior interventricular septal wall visualized in apical 4-chamber view. In a sub-analysis, we evaluated indicators of myocardial perfusion rate comparing subjects with normal vs. those with subnormal ejection fraction (EF). Inter-study reproducibility of assessment of k was relatively low (intraclass correlation coefficient = 0.36), whereas intra-study reproducibility was fair (intraclass correlation coefficient = 0.61). The parameters k X A and B showed higher reproducibility than the k (inter- and intra-study intraclass correlation coefficients 0.64 and 0.75, 0.74 and 0.91, respectively). For reference, reproducibility data of the depth of the region of interest, of EF and CO were excellent. k and k X A were lower in subjects with low vs. those with normal EF. Only k and k X A were lower in subjects with subnormal than in those with normal EF. The MCE-derived indicator of myocardial perfusion rate k X A showed fairly good between-study and between-reading reproducibility.

Left ventricular systolic and diastolic function in aortic stenosis: Prognostic value after valve replacement and underlying mechanisms

The aims of the study were to examine the prognostic value of pre-operative left ventricular systolic and diastolic function on early, and late mortality after valve replacement for aortic stenosis, and to identify possible underlying mechanisms. Ninety-one prospectively recruited consecutive patients with a mean age of 61 years underwent valve replacement for aortic stenosis with concomitant coronary artery bypass grafting in 32 and a minimum postoperative observation period of 5.4 years. There were six early (< or = 30 days postoperatively) and 19 late deaths, and 18 deaths from specific causes (cardiac and prosthetic valve related). Early mortality occurred exclusively among patients with a combined subnormal left ventricular systolic function (subnormal ejection fraction or peak ejection rate, or supranormal time-to-peak ejection--duration of systole ratio) and a subnormal fast filling fraction. In Cox regression models on crude mortality and specific deaths, a subnormal ejection fraction and a fast filling fraction of < or = 45% were the only independent risk factors. Patients with none of these risk factors had normal sex- and age-specific survival, those with any one factor had an early, and those with both factors a massive early and a late excess mortality, with 5-year crude survival of 92%, 77%, and 50%, respectively (P < 0.0001). Systolic wall stress was without prognostic value. Further analyses indicated that impairment of left ventricular function occurred with increasing muscle mass over two phases: (1) diastolic dysfunction characterized by a pattern of severe relative concentric hypertrophy; (2) the addition of systolic dysfunction characterized by a more dilated, less concentric chamber geometry. Coronary artery disease seemed to provoke the latter development sooner. Impaired systolic and diastolic left ventricular function, irrespective of afterload, were decisive independent pre-operative risk factors for early as well as late mortality after aortic valve replacement for aortic stenosis. The adverse influence of concentric hypertrophy was the main underlying mechanism. Operative intervention, before impairment of diastolic and systolic function, should be advocated.

Late noninvasive evaluation of cardiac performance in mildly symptomatic older patients with Ebstein's anomaly of tricuspid valve: Role of radionuclide imaging

Ten patients 8 to 54 years of age with isolated Ebstein's anomaly of the tricuspid valve were evaluated by electrocardiography, maximal exercise treadmill testing, 24 h electrocardiographs (ECG) monitoring, echocardiography and rest radionuclide imaging of the left ventricle. The patients presented after the 1st year of life and had not undergone surgical intervention. All except one were in functional class II. No patient had preexcitation on the surface ECG, but abnormal tachyarrhythmias or bradyarrhythmias were seen in five patients on 24 h ECG monitoring. Subnormal exercise performance was observed in five patients.Echocardiography demonstrated typical variable tricuspid valve displacement and paradoxic interventricular septal motion. Left ventricular end-diastolic dimensions were normal in all patients, but posterior wall motion was reduced in two. Moderate to severe tricuspid regurgitation with a Doppler jet velocity <2.5 m/s was demonstrated in eight patients. Left ventricular radionuclide scintigraphy revealed a subnormal ejection fraction (<50%) in 5 of 10 patients; these 5 had previously shown suboptimal exercise performance.The two youngest patients (<15 years) had no arrhythmia, normal exercise performance and normal left ventricular ejection fraction. There was no correlation between the degree of tricuspid valve displacement or régurgitation and the presence of rhythm disturbance, exercise performance or radionuclide left ventricular function.Late evaluation of patients with Ebstein's anomaly may demonstrate significant unsuspected abnormalities in cardiac rhythm, exercise performance and left ventricular function. Radionuclide scintigraphy is a useful noninvasive technique for assessing left ventricular dysfunction in these patients.

Survival and functional results after valve replacement for aortic regurgitation from 1976 to 1983: impact of preoperative left ventricular function.

Recent studies suggest that preoperative left ventricular function may no longer be an important determinant of survival or functional results after operation for aortic regurgitation because of improved operative techniques. To assess the effect of left ventricular function on prognosis in the current surgical era, we performed echocardiographic and radionuclide angiographic studies in 80 consecutive patients undergoing valve replacement from 1976 to 1983. No patient had associated coronary artery disease. For all patients, 5 year survival was 83 +/- 5%, significantly better than the 62 +/- 9% 5 year survival in our patients operated on from 1972 to 1976. Preoperative resting left ventricular ejection fraction (p less than .001), fractional shortening (p less than .001), and end-systolic dimension (p less than .01) were the most significant predictors of survival (univariate life-table analysis). Five year survival was 63 +/- 12% in patients with subnormal ejection fraction (n = 50) compared with 96 +/- 3% in those with normal ejection fraction (n = 30). Patients with subnormal left ventricular ejection fraction and poor exercise tolerance or prolonged duration of left ventricular dysfunction (greater than 18 months) comprised the high-risk subgroup (5 year survival 52 +/- 11%). Patients in this subgroup also had persistent left ventricular dysfunction after operation, with greater left ventricular end-diastolic dimensions and reduced ejection fraction (both p less than .001) compared with patients with normal preoperative left ventricular ejection fraction or a brief duration of left ventricular dysfunction (less than 14 months). Cold hyperkalemic cardioplegia was used for myocardial preservation in 46 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Function of the hypertrophied left ventricle at rest and during exercise: Hypertension and aortic stenosis

Assessment of left ventricular function may be of value in patients with pressure-loaded, hypertrophied left ventricles for the purpose of characterizing such patients as to prognostic risk. To determine whether left ventricular function is in part independent of loading stresses in such patients, and to assess the effects of removal of loading factors, we have reviewed preliminary data in 60 patients with essential hypertension and in 26 patients with aortic stenosis who were studied with radionuclide cineangiography. Patients with hypertension manifested a poor but statistically significant direct relationship between systolic arterial pressure and left ventricular ejection fraction at rest, and a poor but significant inverse relationship between systolic pressure and the magnitude of change in ejection fraction from rest to exercise. However, a strong correlation existed between echocardiographic systolic fractional shortening and end-systolic wall stress at rest. Nonetheless, many patients with normal fractional shortening-end-systolic wall stress relationships had subnormal ejection fraction responses during exercise; the two patients with subnormal fractional shortening-end-systolic wall stress relationships at rest also had subnormal fractional shortening-end-systolic wall stress relationships during exercise. Arterial pressure alone was not predictive of these functional responses. These data suggest that hypertensive patients can be categorized on the basis of left ventricular function at rest and during exercise, independent of arterial pressure. Among patients with aortic stenosis, ejection fraction at rest averaged 67 percent before valve replacement (normal = 57 percent, p < 0.01), and changed little after operation (71 percent, not significant). However, potential functional benefits of afterload reduction in the patient with the chronically pressure-loaded, hypertrophied left ventricle was suggested by results during exercise: before surgery the ejection fraction during exercise averaged 56 percent (normal = 71 percent, p <0.01), but after valve replacement it rose to 72 percent (not significant versus normal). Thus, our data in patients with aortic stenosis supplement our data in patients with hypertension, indicating that myocardial functional improvement can be achieved by unloading therapy in patients with long-standing left ventricular pressure-loading and hypertrophy.

Preliminary clinical experience with isotonic hypothermic potassium-induced arrest

The modalities of 25 mEq. per liter potassium-induced arrest in a simulated extracellular fluid, and 15° C. perfusion hypothermia were combined and used exclusively for myocardial protection during cardiac surgery in 108 consecutive patients. Over half of the patients had impaired preoperative myocardial function, as assessed by a subnormal ejection fraction and by New York Heart Association Class IV status. Ten patients were semiemergencies and eight were emergencies, including three in cardiogenic shock. The 30-day operative mortality rate was 4.6 percent, and during a mean follow-up of 9 months there were two late deaths-both cerebrovascular. The excellence of the myocardial protection is attested to by spontaneous defibrillation in over 50 percent of the patients, the very infrequent use of pressors, the immediate postoperative improvement in cardiac output, the early improvement in postoperative functional status of almost all of patients, and the very low level of specific myocardial isoenzyme released following the open heart procedures. The significant advantages of 15° C. potassium-induced arrest are (1) simplified high-volume temperature and pressure-monitored aortic root perfusion, effective even with aortic insufficiency, (2) the preclusion of the “calcium paradox,” (3) minimization of defibrillator induced myocardial injury, (4) operating conditions superior to normothermic ischemic arrest or topical hypothermia, (5) avoidance of coronary artery trauma, high and low perfusion pressure injuries, low-flow/high-energy demand situations and low-temperature injury, and (6) extensive clinical and experimental evidence of superior myocardial protection.