Right ventricular size and function: The discrepancy between cardiac blood pool imaging techniques

The purpose of this study was to evaluate a number of equilibrium radionulide methods for analyzing right ventricular size and function, in an attempt to determine if any of a variety of approaches could accurately characterize right ventricular hemodynamics. Fourteen patients being clinically evaluated for coronary artery disease (N = 9), congestive cardiomyopathy (N = 2), valvular disease (N = 2), or intracardiac shunts (N = 1) underwent biplane contrast right ventriculography following gated blood pool imaging. Four radionuclide techniques were examined and included: (1) a semiautomatic edge-detection algorithm using a variable right ventricular region-of-interest and a right ventricular apical end diastolic background; (2) a fixed right ventricular end-diastolic region-of-interest with a C-shaped background; (3) the same fixed end-diastolic right ventricular region-interest with a right ventricular end-diastolic apical background; and (4) both right ventricular end-diastolic and end-systolic regions-of-Interest with a background chosen lateral to the left ventricle. Right ventricular end-diastolic volume was obtained by correcting end-diastolic counts by frame time, the number of processed heart beats, and blood radioactivity. The results illustrate the wide discrepancy among these methods. The correlation coefficients comparing right ventricular ejection fractions by radlonuclide methods 1 to 4 with contrast ventriculography were 0.23, 0.74, 0.40, and 0.42, respectively. For right ventricular end-diastolic volumes, the correlation coefficients were 0.90, 0.72, 0.90, and 0.92, respectively. While these techniques may be useful for analyzing serial changes in right heart function and size, further investigation is needed before right ventricular equilibrium radionuclide techniques can be acceptably utilized in clinical practice, particularly in individual subjects.     

Comparison of radionuclide angiography with three echocardiographic parameters of left ventricular function in patients after myocardial infarction

Aims. Left ventricular function is an important outcome measure in patients with coronary artery disease, in particular in patients after myocardial infarction. It is reliably assessed by radionuclide angiography, but echocardiographic wall motion scoring might be an attractive alternative. Methods. Four days after reperfusion therapy for acute myocardial infarction both radionuclide angiography and echocardiography were performed in 90 patients. Segmental wall motion scoring (WMSI) and visual estimation of the left ventricular ejection fraction (LVEF) was done by 2 independent observers. Repeated analysis was performed 1 month after the first reading. In 41 patients the LVEF was assessed quantitatively by tracing of endocardial outlines of the left ventricle. Results. Both correlation with radionuclide angiography (estimated LVEF: r = 0.71, WMSI: r = – 0.68, Tracing: r = 0.59) and inter- and intra-observer variability (estimated LVEF: 19% and 15%, WMSI: 65% and 59%) were in favour of the LVEF estimation method. Correlation with radionuclide angiography measurements was related to the quality of the echocardiogram and to the extent of coronary artery disease. Conclusion. Simple echocardiographic estimation of left ventricular ejection fraction in patients after reperfusion therapy for acute myocardial infarction proved to be superior to quantitative assessment of ejection fraction and to segmental wall motion scoring in comparison with radionuclide angiography.     

Left ventricular diastolic and systolic function in normotensive obese subjects: influence of degree and duration of obesity.

The present study was carried out to evaluate systolic and diastolic parameters in overweight and moderately obese, but otherwise healthy subjects, and in a lean control group, to determine whether degree and duration of obesity can influence left ventricular function. A total of 27 subjects, 17 overweight or with moderate obesity and 10 lean, healthy subjects were included. Patients were divided into three groups according to their body mass index (BMI) and to Garrow's criteria as follows: lean control group (BMI less than 25 kg.m-2); overweight subjects (BMI from 25 to 30 kg.m-2); moderately obese subjects (BMI greater than 30 less than 40 kg.m-2). Systolic and diastolic parameters were measured using blood pool gated radionuclide angiography. Left ventricular (LV) ejection fraction (EF), peak ejection rate (PER), time to PER (tPER), peak filling rate (PFR) and time to PFR (tPFR) were evaluated. PER and PFR values were normalized for end-diastolic volume (EDV). EF and PFR were significantly lower (P less than 0.05) both in moderately obese and in overweight subjects and tPFR was significantly (P less than 0.05) prolonged in both groups in comparison to lean controls. Only in moderately obese subjects was PER significantly (P less than 0.05) decreased and tPER significantly (P less than 0.05) prolonged in comparison to lean controls. As compared to overweight individuals, moderately obese subjects were characterized by a significant decrease (P less than 0.05) in LVEF and PER and by a significant increase (P less than 0.05) in tPER, without relevant change in PFR and in tPFR.(ABSTRACT TRUNCATED AT 250 WORDS)     

The acute effects of intravenous nisoldipine on left ventricular function within 24 h after acute myocardial infarction.

Nisoldipine is a calcium antagonist with potent coronary vasodilating effects in patients with chronic stable angina pectoris. We studied the acute effects of nisoldipine in six patients within 24 h (mean 14 +/- 4 h) after the onset of myocardial infarction. Nisoldipine was administered as a 4.5 micrograms kg-1 intravenous bolus over 3 min followed by intravenous infusion of 0.2 microgram kg-1 min-1 during 60 min. Radionuclide angiography, cardiac output and intra-arterial blood pressure measurements were performed before and during nisoldipine. Left ventricular ejection fraction increased from 48.3 +/- 10.3% to 55.3 +/- 11.8% (P = 0.034) during nisoldipine infusion. Regional wall motion score changed during nisoldipine infusion from 3.3 +/- 2.5 to 1.8 +/- 2.6 (P = 0.027). Cardiac output increased from 5.5 +/- 1.0 to 7.3 +/- 1.3 l min-1 (P = 0.0001). Heart rate increased from 78 +/- 12 to 88 +/- 11 beats.min-1 (P = 0.004). Mean arterial blood pressure decreased from 91.7 +/- 20.2 to 78.7 +/- 13.1 mmHg (P = 0.038). The rate-pressure product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine improves global and regional left ventricular function in patients with acute myocardial infarction within the first 24 h. Our findings suggest that this effect is achieved without increasing myocardial oxygen demand.     

The acute effects of intravenous nisoldipine on left ventricular function 24 to 72 hours after uncomplicated acute myocardial infarction

Summary The acute effects on left ventricular function of nisoldipine were studied in six patients 56±12 hours (range 44 to 72 hours) after the onset of uncomplicated acute myocardial infarction. Nisoldipine was administered as a 4.5 g/kg intravenous bolus over 3 minutes followed by an infusion of 0.2 g/kg during 60 minutes. Radionuclide angiography and two-dimensional echocardiography were performed before and during infusien with nisoldipine. The left ventricular ejection fraction increased significantly from 38%±10% to 49%±10% (P=0.028) during nisoldipine infusion. Regional wall motion index was determined both by radionuclide and by two-dimensional echocardiography and showed a significant change during nisoldipine infusion from 1.9±0.3 to 1.5±0.3 (p=0.028, radionuclide angiography) and from 0.7±0.2 to 0.3±0.2 (p=0.043, two dimensional echocardiography). Heart rate increased significantly from 78±12 min^-1 to 92±13 min^-1 (p=0.028), but mean double product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine significantly improves global and regional left ventricular function in patients shortly after acute myocardial infarction. This beneficial effect may, however, be partially offset by an increase in heart rate. Since mean double product did not change, it is suggested that nisoldipine may improve coronary blood flow in patients with acute myocardial infarction.     

Estimation of left ventricular systolic function by nonvolumetric echocardiographic analysis in subjects with poor left ventricular visualization: A pilot study

Background: Accurate assessment of left ventricular (LV) systolic function is an essential requirement in clinical cardiology. Several echocardiographic methods provide quantitative analysis of LV volumes and ejection fraction (EF) based on the precise tracing of endocardial borders. Often, however, technically limited studies prohibit such direct analysis, and alternative techniques must be applied. Hypothesis: Nonvolumetric echocardiographic methods which do not require endocardial edge definition and tracing may accurately provide quantitative LV systolic function data. Methods: A pilot study was conducted to validate and compare two recently described indirect echocardiographic methods of LV systolic function analysis, with LVEF by radionu-clear cardiac angiography (RNCA). Thirty-two consecutive patients undergoing RNCA for clinical indications also underwent echocardiography within 24 h, with LV analysis performed by the techniques of (1) atrioventricular plane displacement (AVPD) and (2) mitral valve leaflet coaptation point to interventricular septum distance at end-systole (MVC-IVS). Results: Thirteen patients had an echocardiogram with poor two-dimensional visualization of LV endocardial borders. One patient could not be evaluated by the MVC-IVS method and two others by the AVPD method because of technical limitations. Chi-square analysis to compare how each method could discriminate between an RNCA LVEF of < or ≥ 50% demonstrated high correlations for the AVPD method (r = 0.6530, p < 0.0005) and the MVC-IVS method (r = –0.7029, p < 0.0001). Sensitivity, specificity, positive and negative predictive values, and test accuracy for the AVPD and MVC-IVS methods were 85 and 80%, 88 and 94%, 85 and 92%, 82 and 83%, and 83 and 87%, respectively. Conclusion: This pilot study demonstrates that both alternative echocardiographic methods may be useful in the assessment of LV systolic performance, even in the setting of poor LV endocardial border visualization. A larger study is warranted to apply and contrast these methods in different patient subsets.     

Left ventricular function and exercise capacity in patients with slow coronary flow

Background: Endothelial and microvascular dysfunction have been implicated in slow coronary flow (SCF). How and to what extent do these etiological factors affect left ventricular (LV) function and exercise capacity? Aim: The aim of the study was to evaluate LV systolic and diastolic function by pulsed tissue Doppler imaging (TDI) in SCF patients and their effects on exercise capacity. Subjects and methods: Sixty SCF patients and 20 control subjects were included in the study. Echocardiographic examination, treadmill exercise test, and TDI were performed. Isovolumic myocardial acceleration (IVA) and myocardial performance index (MPI) were measured. Results: TDI mean parameters for systolic and diastolic LV function were significantly impaired in SCF group with decreased Sa, IVA, Ea/Aa, and increased MPI (0.31 ± 0.06 vs. 0.26 ± 0.04, P < 0.01) compared to control. There was significant correlation between thrombolysis in myocardial infarction (TIMI) frame count and TDI mean parameters for LV systolic function (Sa & IVA, r =?0.53, P < 0.01 & r =?0.36, P < 0.05, respectively). Mean TIMI frame count was correlated with MPI and E/Ea. SCF patients had poorer peak exercise capacity than the controls (9.9 ± 1.9 METs vs. 12.7 ± 2.3, P < 0.01) with significant negative correlation with mean TIMI frame count (r =?0.46, P < 0.01). Conclusion: There is impairment of LV systolic and diastolic function in SCF patients with clinical impact on exercise capacity which emphasizes the importance of close follow‐up of these patients for risk stratification. (Echocardiography 2012;29:158‐164)     

Left ventricular diastolic and systolic function during isometric exercise: an echocardiographic study

Normal subjects of both sexes between 20 and 63 years were examined with M-mode echocardiography. Blood pressure (BP), heart rate (HR), and left ventricular (LV) diastolic and systolic function were measured at rest and at the end of a standardized maximal isometric handgrip test. BP and HR increased about 25%. This increase in cardiac work had no significant influence on LV systolic function. Diastolic function (myocardial relaxation and maximum rate of LV filling), however, improved significantly. Isometric handgrip test is a suitable exercise test in combination with M-mode echocardiography. Studies on LV function during exercise may improve the sensitivity for detection of mild LV dysfunction.     

Left ventricular systolic and diastolic function after anthracycline chemotherapy in childhood

BACKGROUND: In childhood, late cardiotoxicity is characterized by inappropriately thin wall and consequent increased end-systolic wall stress, but the associations of impaired left ventricular geometry and function occurring under these circumstances need further investigation. HYPOTHESIS: The purpose of this study was to assess anthracycline late effects on the relationships occurring between increased end-systolic stress (ESS) and changes in both M-mode systolic measurements (i.e., endocardial and midwall fractional shortening) and Doppler diastolic indices in the pediatric age. METHODS: The population consisted of 101 children treated with anthracyclines for at least 12 months and 91 healthy children. Using M-mode echocardiography, end-systolic wall stress was calculated as index of afterload, and endocardial and midwall fractional shortening as systolic indices. Doppler transmitral measurements were made as diastolic indices. RESULTS: Patients treated with anthracyclines showed significantly lower relative wall thickness and left ventricular mass index, greater end-systolic wall stress, reduced endocardial and midwall fractional shortening and peak E/A ratio, prolonged deceleration, and isovolumic relaxation times. Direct relationships were found between end-systolic wall stress and both endocardial and midwall shortening. The use of midwall shortening in the relation showed a greater, but not significant increase (from 3 to 6%) in the proportion of patients with depressed systolic function than did endocardial shortening. In the anthracycline group, end-systolic wall stress was also inversely related to relative wall thickness and directly to isovolumic relaxation time. CONCLUSIONS: In childhood, reduced myocardial thickness and increased afterload explain much of systolic and diastolic dysfunction of late anthracycline toxicity. Midwall fractional shortening does not seem to add useful information for identifying subsets of children more prone to the development of heart failure.     

Effects of angiographic contrast medium on left ventricular function: Evaluation by contrast angiography and radionuclide angiography

The purpose of this study was to evaluate the effect of angiographic contrast medium on left ventricular (LV) function in 26 patients undergoing diagnostic cardiac catheterization. Beat-by-beat analysis during contrast ventriculography showed that the ejection fraction (EF) was lower in the last beats than in the first beats (P <.02). Radionuclide angiograms were obtained the day before, as well as 15 to 65 minutes after catheterization, which included contrast ventriculography and coronary anteriography. The EF by radionuclide angiography was lower after catheterization than before (43 ± 14% vs 47 ± 17%, P <.01). The EF decreased by ≥ 5% in 11 of the 26 patients (42%) after catheterization. The decrease in EF in some patients was observed up to 65 minutes after catheterization and was not associated with symptoms or ST-T changes. The EF decreased in only one of nine patients who received nitroglycerin during catheterization, whereas it decreased in 10 of 17 patients who did not receive nitroglycerin (P <.05). The EF decreased in 9 of 14 patients (64%) who had normal resting LV function, whereas it decreased in only 2 of 12 patients (17%) who had abnormal resting function (P <.05). Thus, contrast material may depress LV function up to 1 hr and is more frequent in patients with normal resting EF. The use of nitroglycerin during catheterization may mask this effect.     

Left ventricular function during transient coronary occlusion: digital subtraction left ventriculograms during coronary angioplasty

The impact of transient myocardial ischemia on left ventricular function was examined by digital subtraction left ventricular angiography. Contrast medium was injected into the right pulmonary artery before, at 60 seconds of balloon inflation, and 10 minutes after balloon deflation. A total of 69 patients completed the study. In 52 patients, the left anterior descending artery (LAD) was involved, and in 17, the right coronary artery (RCA) was the focus. Ejection fraction (EF) declined by balloon inflation and returned to baseline value after deflation of the balloon. There was tendency toward a lower EF and wider akinetic area for LAD dilatation. The linear correlation between resting EF and EF during balloon inflation suggested that the effect of momentary coronary occlusion on left ventricular function appears to be additive to pre-existing left ventricular dysfunction, and resting ejection fraction is an important parameter for estimating the degree of diminished left ventricular function during myocardial ischemia.     

Left atrial dissection after left ventricular aneurysm repair

Left atrial (LA) dissection is an uncommon entity that occurs most often after mitral valve surgery. We present a case of a 52-year-old man who developed an LA dissection after repair of a postinfarction left ventricular (LV) aneurysm. Transesophageal echocardiography was used to establish the diagnosis of an LA dissection that almost completely occluded the LA, limiting LV filling and causing hemodynamic instability.     

Left ventricular aneurysm: clinical and hemodynamic data

Clinical and hemodynamic data of 30 patients with left ventricular aneurysm (27 men, 3 women, mean age 54.9 years) were compared with those of 30 patients with previous myocardial infarction and segmental hypo- or akinesis (28 men, 2 women, mean age 51 years). In each group, 10 patients were affected by one-, two-, or three-vessel disease. A semiquantitative evaluation of collateral coronary circulation showed no significant differences between the two groups. Mean end-diastolic volume was higher in patients with left ventricular aneurysm (p less than .025, less than .05, and less than .001 in 1-, 2-, and 3-vessel disease, respectively) and ejection fraction was lower only in patients with one-, (p less than .001) and two- (p less than .05) vessel disease in comparison with patients without left ventricular aneurysm. No significant difference was evidenced in basal or isometric exercise end-diastolic pressure. The incidence of thrombosis detected by ventriculography was higher in patients with left ventricular aneurysm (33.3 vs. 6.6%). The mean duration of follow-up was 20.7 months in patients with left ventricular aneurysm and 20.6 in the control group. No significant difference was found either in mortality or in reinfarction rate as far as incidence and severity of angina. The incidence of congestive heart failure was more evident, but not significant in patients with left ventricular aneurysm. One embolic episode was present in one patient with aneurysm and intraventricular thrombosis. Left ventricular performance is influenced by an aneurysm when a limited coronary compromise is present (one- and two-vessel disease) while it is not affected in the case of a coexisting three-vessel disease.     

Analysis of left ventricular function from gated first-pass and multiple gated equilibrium acquisitions

^99mTechnetium-sestamibi is a new myocardial perfusion imaging agent that offers significant physical advantages over²⁰¹thallium for myocardial perfusion imaging. One of these advantages is that it can be used in the assessment of ventricular function by means of first-pass radionuclide angiography (FPRNA), acquired during the injection of the tracer. In this study we compared gated list mode first-pass acquisition with^99mTc-sestamibi (FP-MIBI) to multiple gated equilibrium radionuclide ventriculography (MUGA) with^99mTc-labelled red blood cells for the determination of global left ventricular ejection fraction (LVEF). The study population consisted of 20 patients (mean age 54 years) who were submitted to stress-rest perfusion imaging. Resting FPRNA was performed using^99mTc-sestamibi and the reference data were acquired within a week with the MUGA technique. A linear correlation between FP LVEF and MUG A LVEF gave an r=0.974 (p<0.01). Diastolic and systolic timing and velocity parameters had lower correlations between these two methods. We conclude thatglobal LVEF can be precisely measured with^99mTc-sestamibi when compared to usually employed MUGA technique with^99mTc-labelled red blood cells.     

Left ventricular systolic function after marked reduction of ventricular hypertrophy induced by 5 years' enalapril treatment

OBJECTIVES: To determine the effects of long-term treatment of essentialhypertension with an angiotensin-converting enzyme inhibitoras regards arterial pressure at rest and during exercise, leftventricular mass and functional sequelae. PATIENTS AND METHODS: Twenty-six patients with previously untreated essential hypertensiontook enalapril 20 mg twice daily for 5 years. Cardiovascularparameters were determined by two-dimensionally guided M-modeechocardiography in a pre-treatment placebo phase, 8 weeks and1, 3 and 5 years after the start of therapy, and 8 weeks afterdrugs were discontinued. RESULTS: Therapy reduced resting arterial pressure from 156/105 to 128/84mmHg (P<0.001) and arterial pressure during exercise from205/113 to 172/94 mmHg (P<0.0011). After 1, 3 and 5 years'therapy, left ventricular mass index had decreased by 15, 28and 39% respectively (P<0.001 in each case). Eight weeksafter treatment was halted, arterial pressure at rest and duringexercise had returned to pre-treatment values, but decreasedleft ventricular mass was maintained Left ventricular pump functionhad improved after 5 years' treatment, and this improvementwas maintained during the 8 weeks without treatment. CONCLUSIONS: Significant reductions in arterial pressure at rest and duringexercise were achieved by 8 weeks' treatment with enalapriland maintained during 5 years' further treatment, while a markedreduction in left ventricular mass took place progressivelythroughout the 5 year period. Reduction of myocardial hypertrophyby enalapril appeared to be beneficial rather than detrimentalto cardiac pump performance.     

Left ventricular systolic function after marked reduction of ventricular hypertrophy induced by 5 years' enalapril treatment

OBJECTIVES:: To determine the effects of long-term treatment of essentialhypertension with an angiotensin-converting enzyme inhibitoras regards arterial pressure at rest and during exercise, leftventricular mass and functional sequelae. PATIENTS AND METHODS:: Twenty-six patients with previously untreated essential hypertensiontook enalapril 20 mg twice daily for 5 years. Cardiovascularparameters were determined by two-dimensionally guided M-modeechocardiography in a pre-treatment placebo phase, 8 weeks and1, 3 and 5 years after the start of therapy, and 8 weeks afterdrugs were discontinued. RESULTS:: Therapy reduced resting arterial pressure from 156/105 to 128/84mmHg (P<0·001) and arterial pressure during exercisefrom 205/113 to 172/94 mmHg (P<0·0011). After 1, 3and 5 years' therapy, left ventricular mass index had decreasedby 15, 28 and 39% respectively (P<0·001 in each case).Eight weeks after treatment was halted, arterial pressure atrest and during exercise had returned to pre-treatment values,but decreased left ventricular mass was maintained Left ventricularpump function had improved after 5 years' treatment, and thisimprovement was maintained during the 8 weeks without treatment. CONCLUSIONS:: Significant reductions in arterial pressure at rest and duringexercise were achieved by 8 weeks' treatment with enalapriland maintained during 5 years' further treatment, while a markedreduction in left ventricular mass took place progressivelythroughout the 5 year period. Reduction of myocardial hypertrophyby enalapril appeared to be beneficial rather than detrimentalto cardiac pump performance.     

Left ventricular volumes in the recovery phase after myocardial infarction: relation to infarct location, left ventricular function and one-year cardiac mortality

Absolute left ventricular volumes, normalized to body surface area, were determined by a count-based radionuclide technique in 189 patients with myocardial infarction (MI). All examinations were performed in the second week after MI. Fifty-three percent of the patients had an increased end-diastolic volume index (EDVI) and 72% an increased end-systolic volume index (ESVI). Patients with anterior MI had the same median EDVI as patients with inferoposterior MI, but significantly higher median ESVI and significantly lower median stroke volume index (SVI). SVI was subnormal in 19% of the 189 patients and left ventricular ejection fraction (LVEF) was subnormal in 67%. A non-linear, inverse relationship was present between EDVI and LVEF and between ESVI and LVEF, but LVEF varied greatly for any degree of ventricular dilatation. During a 1-year follow-up period, death from cardiac causes occurred in 29 patients. A strong relationship was present between the degree of ventricular dilatation and 1-year mortality, as well as between the degree of SVI or LVEF reduction and 1-year mortality but, next to clinical heart failure, LVEF was the single most powerful predictor of cardiac death, and various combinations of EDVI, ESVI and SVI did not add more prognostic information to that obtained by heart failure than did LVEF.     

Effects of molsidomine on global and regional left ventricular function at rest and during exercise in patients with angina pectoris

Although the antianginal properties of molsidomine are well-established, little is known about its effects on global and regional left ventricular dysfunction secondary to myocardial ischemia. In the present study, left ventricular performance was assessed by radionuclide ventriculography at rest and during exercise in 15 patients with coronary artery disease (CAD) and angina pectoris before and after the administration of 2 mg molsidomine sublingually. Gated blood pool studies were performed for evaluation of left ventricular ejection fraction (LVEF) and regional wall motion by analyzing amplitudes and phases of the first Fourier coefficient of regional time–activity curves. In contrast to normal subjects, during the control study period LVEF in patients with CAD decreased from 50.9% at rest to 42.7% during exercise (p<0.01). After molsidomine the resting values of LVEF increased slightly from 50.9% to 55.7% (p<0.05). Exercise values of LVEF increased from 42.7% to 51.3% (p<0.01). This is usually associated with amelioration of anginal pain and ischemic ST depression in the precordial ECG (0.15 mV vs. 0.09 mV; p<0.01). Before molsidomine, regional wall motion deteriorated from rest to exercise in 11 of 15 patients. These wall motion abnormalities usually expressed themselves as newly developed regions of left ventricular dysfunction (8 patients) or as accentuation of pre-existing contraction disturbances (3 patients). After molsidomine, regional wall motion did not show consistent changes at rest. Comparison during exercise showed enhanced regional function in 10 of the 15 patients after administration of the drug. At rest a slight but significant increase in heart rate was measured following molsidomine, whereas exercise heart rate remained unchanged. Only minor changes in systolic blood pressure occurred after molsidomine (rest, 143 mmHg vs. 134 mmHg; p<0.05; exercise, 177 mmHg vs. 174 mmHg; p>0.10). In conclusion, assessment of left ventricular performance at rest and during exercise in patients with CAD revealed significant improvement of global and regional left ventricular function, indicating reduction of myocardial ischemia. These effects may result primarily from reduction of left ventricular wall tension.