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PubMed2004

Increased left ventricular mass is a risk factor for the development of a depressed left ventricular ejection fraction within five years: the Cardiovascular Health Study.

OBJECTIVES: Our aim in this study was to determine whether increased left ventricular mass (LVM) is a risk factor for the development of a reduced left ventricular ejection fraction (LVEF). BACKGROUND: Prior studies have shown that increased LVM is a risk factor for heart failure but not whether it is a risk factor for a low LVEF. METHODS: As part of the Cardiovascular Health Study, a prospective population-based longitudinal study, we performed echocardiograms upon participant enrollment and again at follow-up of 4.9 +/- 0.14 years. In the present analysis, we identified 3,042 participants who had at baseline a normal LVEF and an assessment of LVM (either by electrocardiogram or echocardiogram), and at follow-up a measurable LVEF. The frequency of the development of a qualitatively depressed LVEF on two-dimensional echocardiography, corresponding approximately to an LVEF <55%, was analyzed by quartiles of baseline LVM. Multivariable regression determined whether LVM was independently associated with the development of depressed LVEF. RESULTS: Baseline quartile of echocardiographic LVM indexed to body surface area was associated with development of a depressed LVEF (4.8% in quartile 1, 4.4% in quartile 2, 7.5% in quartile 3, and 14.1% in quartile 4 [p < 0.001]). A similar relationship was seen in the subgroup of participants without myocardial infarction (p < 0.001). In multivariable regression that adjusted for confounders, both baseline echocardiographic (p < 0.001) and electrocardiographic (p < 0.001) LVM remained associated with development of depressed LVEF. CONCLUSIONS: Increased LVM as assessed by electrocardiography or echocardiography is an independent risk factor for the development of depressed LVEF.

Aged↗

PubMed2001

Aspirin does not influence the effect of angiotensin-converting enzyme inhibition on left ventricular ejection fraction 3 months after acute myocardial infarction.

The aim of the present study was to evaluate the possible interaction between chronic aspirin therapy and angiotensin-converting enzyme inhibitor (ACE-I) on left ventricular ejection fraction (LVEF) in patients surviving an acute myocardial infarction (AMI). Forty-two patients with reduced LVEF were recruited from the warfarin aspirin reinfarction study (WARIS-II), a randomized, open study comparing enteric coated aspirin (160 mg/d), warfarin (INR 2.8--4.2) and the combination of aspirin (75 mg/d) and warfarin (INR 2.0--2.5) on mortality, reinfarction and stroke after AMI. LVEF and relevant biochemical measurements were performed before discharge and after 3 months. The overall LVEF increased during the study period from median 35 to 39% (P<0.001). There was no difference between patients on aspirin and warfarin regarding the main end point, LVEF. Furthermore, neither endothelin-1 nor ANP showed significant differences between the treatment groups. A possible interaction between ACE-I and aspirin might theoretically lead to reduced levels of renin activity in patients on aspirin, but we did not find any such inter-group difference. In conclusion, we did not find evidence of interaction between ACE-I and low-dose aspirin.

Adult↗

PubMed1999

Left ventricular remodelling in post-myocardial infarction patients with left ventricular ejection fraction 40-50% vs 25-39%. Influence of nisoldipine treatment? An echocardiographic substudy from the DEFIANT II study.

OBJECTIVE: Left ventricular (LV) remodelling following acute myocardial infarction has generally been studied in patients with LV ejection fraction (EF) < 40%, and it has been shown that this process can be attenuated by ACE inhibitors. Little is known regarding LV remodelling in patients with LVEF > or = 40% or the effects of treatment in this patient cohort. The DEFIANT II study (Doppler Flow and Echocardiography in Functional cardiac insufficiency) included 542 post-infarction patients with LVEF 25-50% without overt heart failure within 13 days following acute myocardial infarction (AMI). They were then randomized to nisoldipine coat-core (CC) or placebo and followed up for 6 months. DESIGN: Two-dimensional echoes were obtained after 8 (5-13) days and 6 months following AMI. SETTING: LV end diastolic (ED) and end systolic (ES) volumes (V) were calculated in 503 patients with technically satisfactory paired echoes using the biplabe method of discs in a core laboratory. SUBJECTS: Group A. 217 patients with baseline EF 40-50%, of whom 112 were randomized to nisoldipine and 104 to placebo (one patient was taken off study medication). Group B. 286 patients with EF 25-39%, of whom 145 were randomized to nisoldipine and 141 to placebo. RESULTS: LVEDV was 175 (+/-45) ml in Group A vs 203 (+/-49) ml in Group B (p = 0.001) at baseline and 184 (+/-48) ml vs 213 (+/-56) ml (p = 0.001), respectively, at 6 months. LVESV at baseline was 97 (+/-42) ml in Group A vs 133 (+/-37) ml in Group B (p = 0.001), and 106 (+/-34) ml vs 134 (+/-45) ml (p = 0.001) at 6 months, respectively. The increase of LVESV was 9 (+/-29) ml in Group A vs 2 (+/-35) ml in Group B (p = 0.007). LVEF decreased by 2 (+/-6)% in Group A vs an increase of 3 (+/-6)% in Group B (p = 0.001). Treatment with nisoldipine had no influence on LV volumes in either of the two groups or in the total study group. CONCLUSION: LV dilatation 6 months following AMI in patients with EF 40-50% was similar in end diastole, but more pronounced in end systole vs patients with EF 25-39%. LV remodelling did not change significantly after nisoldipine treatment.

Adult↗

PubMed2006

Contraction-relaxation coupling mechanism characterization in the thermodynamic phase plane: normal vs. impaired left ventricular ejection fraction.

Using simultaneous pressure-volume measurements obtained during cardiac catheterization, we employ the thermodynamic phase-plane (TPP) method to characterize global contraction-relaxation coupling (CRC) between normal and impaired left ventricular (LV) ejection fraction (LVEF) groups. The cardiac cycle inscribes a closed loop in the TPP defined by the coordinates "potential" power [V(dP/dt), ergs/s] and "kinetic" power [P(dV/dt), ergs/s]. The TPP-derived indexes kappa and rho define the chamber's contractile and CRC attributes, respectively. Data from 33 subjects dichotomized as normal control (n = 22, >50% LVEF) and impaired LVEF (n = 11, <50% LVEF) were analyzed. The results were as follows: kappa = 3.0 +/- 1.1 and rho = -0.38 +/- 0.21 for controls and kappa = 5.4 +/- 1.6 and rho = -1.14 +/- 0.47 for the impaired LVEF group; kappa and rho are significantly higher for impaired LVEF than for control (P < 0.001 for both). As kappa increased, rho decreased (r = -0.69) for all subjects. Hence, ventricles with impaired LVEF are thermodynamically less efficient because they require more potential power per unit of delivered kinetic power than controls. We conclude that TPP-derived indexes of CRC facilitate assessment of chamber efficiency in thermodynamic terms and elucidate the dominant differentiating features in terms of CRC indexes.

Animals↗

PubMed1978

Varying ejection fractions of both ventricles in paradoxical pulses: demonstration by radionuclide study.

A noninvasive radionuclide study of the paradoxical pulse in pericardial effusion is described. The study shows complementary changes of the right and left ventricular ejection fractions in a patient with paradoxical pulse, supporting the theory that the inspiratory reduction of the left ventricular stroke volume is an immediate and direct result of the inspiratory increase of the right ventricular filling. The technique may be sensitive to detect early paradoxical pulse and cardiac tamponade.

Adult↗

PubMed1992

[Noninvasive evaluation of cardiac index and ejection fraction in ischemic heart disease. Comparison of thoracic bioimpedance, thermodilution and cineventriculography].

Aim of the study was to verify the reliability of thoracic bioimpedance cardiography (TEB) in detection, non-invasively, cardiac index (IC) and ejection fraction (FE), compared to simultaneous evaluation by invasive thermodilution (TD) in 39 patients with acute myocardial infarction in Killip class I-II (group I), and by cineventriculography (CVG) in 26 patients with chronic coronary artery disease in NYHA class I-II (group II). In order to define the reproducibility of TEB values, in the latter patients, the above mentioned parameters were evaluated 6 times more, running the first evaluation. The statistical analysis was performed by the linear regression test and the Student's "t" test and by the test of variance for the reproducibility evaluation. Results (mean +/- SD) were as follows: group I: TEB-IC 2.89 +/- 0.63; TD-IC 2.83 +/- 0.56 (1/min/m2); r = 0.68; p < 0.01. Group II: TEB-IC 2.88 +/- 0.71; CVG-IC 3.48 +/- 0.66; r = 0.77; p < 0.001; TEB-FE 57.7 +/- 6.8%; CVG-FE 58.1 +/- 13.7%; r = 0.40; p = ns. Results of the reproducibility referred to the 6 measurements (mean +/- SD) were the follows: TEB-IC (1/min/m2) (1) 2.83 +/- 0.76; (2) 2.85 +/- 0.73; (3) 2.8 +/- 0.79; (4) 2.83 +/- 0.71; (5) 2.87 +/- 0.81; (6) 2.88 +/- 0.8, p = ns, the variability was assesses within +/- 9.3%. TEB-FE (%): (1) 56.7 +/- 6.2; (2) 55.8 +/- 5; (3) 57.1 +/- 5.5; (4) 56.1 +/- 6.1; (5) 55.4 +/- 5.8; (6) 57.3 +/- 6.3, p = ns; the variability was assessed within +/- 9.1%. The analysis of the results showed a good correlation in the IC detection among TEB and the compared techniques, conversely TEB evaluation of FE appear of poor values in this kind of patients. Relatively to the results of the reproducibility this unquestionable characteristic of TEB was demonstrated.

Aged↗

PubMed2006

[Heart failure with preserved ejection fraction. Effect of etiology on prognosis].

INTRODUCTION AND OBJECTIVES: Heart failure with preserved systolic function accounts for almost 40% of heart failure cases. Prognosis is similar to that in patients with a low left ventricular ejection fraction (LVEF). However, it is not clear whether the etiology of heart failure with preserved systolic function has an effect on prognosis. METHODS: We assessed 95 consecutive patients admitted to our hospital with heart failure and a LVEF>45%. Twenty-five (26%) had an ischemic etiology and 70 (74%), a non-ischemic etiology. RESULT: The patients' mean age was 73 (6) years, 60% were female, and their mean LVEF was 61 (7)%. These characteristics were similar in the two etiological groups. After a mean follow-up period of 53 (8) months (4-69 months; median 46 months), mortality was higher in ischemic patients (17.88 vs 2.37/100 patient-years; P<.0001), as was the rate of cardiovascular admissions (24.58 vs 4.14/100 patient-years; P<.0001). The rates of mortality due to heart failure and sudden death were also higher in ischemic patients, at 7.82 vs 0.59/100 patient-years, and 7.82 vs 0.30/100 patient-years, respectively (P<.0001). The higher overall admission rate found in the ischemic group was due to higher rates of admission for heart failure (14.53 vs 0.89/100 patient-years; P<.0001) and acute coronary syndrome (8.94 vs 1.78/100 patient-years; P=.003). CONCLUSIONS: In terms of prognosis, heart failure with preserved systolic function is not a homogeneous disease entity. Morbidity and mortality rates are higher in patients with an ischemic etiology. Moreover, different mechanisms are involved.

Aged↗

PubMed2006

Heart failure update: treatment of heart failure with a normal left ventricular ejection fraction in the elderly.

Heart failure (HF) affects approximately 5 million persons in the United States; more than 550,000 new cases of HF are reported each year. Prevalence of HF with a normal left ejection fraction increases with age and is higher in older women than older men. Both underlying and precipitating causes of HF should be treated when possible. Hypertension, especially isolated systolic hypertension, should be treated with diuretics, ACE inhibitors, and beta blockers. Myocardial ischemia should be treated with nitrates and beta blockers. Anemia should be treated, as should hyperthyroidism, hypothyroidism, and obstructive sleep apnea. Use of inappropriate drugs, such as nonsteroidal anti-inflammatory drugs, should be avoided. Coronary revascularization should be performed in selected individuals.

Adrenergic beta-Antagonists↗

PubMed1995

[Response of the left ventricular ejection fraction,assessed by by radionuclide angiography, to inotropic stimulation: its relationship with the reversibility of perfusion defects in thallium-201 scintigraphy with overload-reinjection protocol].

BACKGROUND: Reversibility of perfusion defects and left ventricular (LV) ejection fraction (LVEF) response to low-dose catecholamines may reflect complementary aspects of myocardial viability, in patients with CAD and LV dysfunction in whom revascularization is considered. OBJECTIVE: To evaluate the relationship between LVEF response to inotropic stimulation with adrenaline (delta LVEF) and myocardial perfusion. DESIGN AND SETTING: Prospective study in a cardiology department with referral for revascularization and transplantation. PATIENTS: 45 patients (pt) with compromised LVEF (< 45%) after myocardial infarction (MI). METHODS: Radionuclide ventriculography at baseline and during graded adrenaline infusion until 12 micrograms/min: an empirical cut-off value of delta LVEF of 8% was used to define groups with (CR+) or without (CR-) contractile reserve. Stress-reinjection 201TI SPECT: perfusion was classified with a weighted score based on visual analysis of extent and intensity of thallium uptake in five major myocardial segments, with results expressed as percent of myocardium classified as normal (%N), with fixed defects (%F), and with reversibility (%R). MAIN RESULTS: Groups CR+ (23 pt) and CR- (22 pt) had similar baseline LVEF (29.6 +/- 7.4 and 26.4 +/- 8.1), while delta LVEF was respectively 13.6 +/- 4.6 and 2.9 +/- 3.3. When compared to the other group, CR+ patients had, in average, 1.0 segment more with definite reversibility and 1.6 segments less with fixed defects; in terms of percentage of myocardium, CR+ patients had more extensive reversible areas (%R: 15.3 +/- 11.7 vs 4.7 +/- 5.0, p < 0.001), smaller irreversible areas (%F: 30.7 +/- 14.5 vs 45.6 +/- 16.1, p = 0.02) and similar extent of normal areas (54.0 +/- 14.6 vs 49.7 +/- 16.4). Patients with more extensive fixed defects had worse delta LVEF in response to adrenaline (p < 0.002, r = -0.45). Greater %R was positively correlated with delta LVEF (p < 0.02, r = 0.35). In all patients, delta LVEF with adrenaline was superior or equal to (%R/2)-10. No patient with %R > or = 15 had delta LVEF < 8%. However, ten patients had delta LVEF > or = 8% despite lesser degrees of %R. CONCLUSION: Our data suggest a clear association between myocardial inotropic reserve and the extent of potentially viable myocardium (as evaluated by stress-reinjection thallium SPECT), in patients with left ventricular dysfunction after myocardial infarction. Further assessment is needed to clarify the relative role of radionuclide ventriculography with inotropic stimulation in viability evaluation, notably with inclusion of regional wall motion information and with reassessment of patients after revascularization, when performed.

Adult↗

PubMed1997

[The effects of thoracic epidural anesthesia combined with phentolamine infusion in a patient with low left ventricular ejection fraction undergoing resection of aortic abdominal aneurysm].

The subject was a 73 year old man scheduled for resection of abdominal aortic aneurysm. The patient had a past history of myocardial infarction and his left ventricular ejection fraction was 21%. Anesthesia was maintained with thoracic epidural anesthesia combined with light general anesthesia using NLA technique. Phentolamine was infused for after-load reduction. We maintained the intravascular volume with infusion therapy and mild hemodilution was performed. As the result of these procedures, systemic vascular resistance decreased and cardiac index increased after the induction of anesthesia. Forrester classification was subset I at any point during the surgery. Hemodynamic changes were not significant after clamping and unclamping of the aorta. We conclude that successful anesthetic management of this patient was due to the epidural anesthesia and combined use of phentolamine as a vasodilator.

Aged↗

PubMed1991

Late outcome of survivors of out-of-hospital cardiac arrest with left ventricular ejection fractions greater than or equal to 50% and without significant coronary arterial narrowing.

In a retrospective survey of 1,195 survivors of out-of-hospital ventricular fibrillation, 43 patients were identified in whom left ventricular ejection fraction was greater than or equal to 0.50 and in whom no coronary artery stenosis of greater than or equal to 50% luminal diameter were present. Thirteen (30%) of these patients had hypokinesia on left ventriculography, and 20 patients (47%) had a persistently abnormal electrocardiogram. Seven patients (16%) had recurrent out-of-hospital cardiac arrest during an average follow-up of 86 +/- 54 months. The presence of either wall motion or electrocardiographic abnormalities defined patients with a several-fold higher risk of recurrent cardiac arrest than those without such abnormalities. The risk for recurrent cardiac arrest within 5 years was 30% in those with abnormal electrocardiograms versus 5% in the others (p less than 0.03). Age was an independent predictor of recurrent cardiac arrest in this group (p less than 0.01); surprisingly, recurrent cardiac arrest was occurring more often among younger patients. Although cardiac arrest is unusual in patients without major structural heart disease, its recurrence in such survivors is common. Patients at relatively high risk for recurrent ventricular fibrillation can be identified by their youth and by abnormalities detected on the surface 12-lead electrocardiogram or by contrast left ventriculography.

Adult↗

PubMed2005

Comparative accuracy of color M-mode and tissue Doppler echocardiography in the emergency diagnosis of congestive heart failure in chronic hypertensive patients with normal left ventricular ejection fraction.

The accuracy of the tissue Doppler E/Ea and color M-mode Doppler E/Vp indexes in diagnosing congestive heart failure (HF) was investigated in 20 chronic hypertensive patients with acute dyspnea and normal left ventricular ejection fractions who met Vasan's criteria for definite diastolic HF, compared with 20 gender- and age-matched hypertensive patients with noncardiac cause of acute dyspnea. The E/Ea ratio appeared to be more reproducible (variability 4% to 9% vs 6 to 14%) and more precise (sensitivity 77.8%, specificity 100%, and accuracy 89.5% for the optimal cutoff of 11 vs sensitivity 73.7%, specificity 75%, and accuracy 74.3% for the optimal cutoff of 1.5) than the E/Vp ratio in this clinical setting.

Aged↗

PubMed1999

Comparison of measurement of left ventricular ejection fraction by Tc-99m sestamibi first-pass angiography with electron beam computed tomography in patients with anterior wall acute myocardial infarction.

The goal of this study was to compare measurements of left ventricular (LV) ejection fraction (EF) by first-pass radionuclide angiography ("first-pass angiography") using technetium-99m (Tc-99m) sestamibi with those by contrast-enhanced electron beam computed tomography ("electron beam tomography") as a reference technique in patients with an anterior wall acute myocardial infarction (AMI). Twenty-five patients with first Q-wave anterior wall AMI underwent paired electron beam tomographic and first-pass angiographic studies (mean, 1 day apart). Fourteen patients had 2 sets of measurements of the LVEF obtained by both methods (separated by at least 6 weeks), for a total of 39 paired measurements. LVEF by electron beam tomography was calculated from absolute systolic and diastolic LV chamber volumes. LV volumes by electron beam tomography were 199 +/- 51 ml at end-diastole and 111 +/- 42 ml at end-systole. Mean LVEF was 45 +/- 11% by first-pass tomography and 46 +/- 9% by electron beam tomography. The linear correlation coefficient between both methods was 0.82 (p <0.0001), with slope = 1.0, y-intercept = -1.1, and SEE = 6.1. The mean difference between the 2 methods was -0.7 +/- 6.0 EF units (p = 0.75). The correlation between the differences and means of both methods was 0.34 (p = 0.04), indicating a trend for first-pass angiography to overestimate LVEF in the higher range. LVEFs measured by first-pass angiography in patients with abnormal LV geometry and contraction patterns caused by anterior wall AMI agree well with those measured by electron beam tomography in the clinically relevant range.

Female↗

PubMed2000

Long term prognosis after CABG in relation to preoperative left ventricular ejection fraction.

AIM: To evaluate the mortality rate, risk indicators for death, mode of death and symptoms of angina pectoris during 5 years after coronary artery by pass grafting (CABG) in relation to the preoperative left ventricular ejection fraction (LVEF). PATIENTS: All patients in western Sweden who underwent CABG without concomitant valve surgery and without previously performed CABG between June 1988 and June 1991. RESULTS: In all 1904 patients were included in the analysis, of whom 173 (9%) had a LVEF < 40%. Patients with LVEF > or = 40% had a 5-year mortality of 12.5%. LVEF < 40% was associated with an increased risk of death (RR 2.3; 95% cl 1.7-3.1). There was no significant interaction between age, sex or any other factor in terms of clinical history and LVEF. However, left main stenosis was a strong independent predictor of death among patients with LVEF < 40% but not in those with a higher LVEF. Patients with a low LVEF more frequently died a cardiac death and a death associated with myocardial infarction (AMI). Furthermore they more frequently died in association with congestive heart failure and ventricular fibrillation. Among survivors, symptoms of angina pectoris were similar regardless of the preoperative LVEF. CONCLUSION: Patients with a low preoperative LVEF have a more than two-fold increased risk of death during 5 years after CABG. Their increased risk of death includes cardiac death, death associated with AMI, congestive heart failure and ventricular fibrillation.

Angina Pectoris↗

PubMed2003

Estimation of left ventricular ejection fraction from Doppler derived myocardial performance index in patients with acute myocardial infarction: agreement with echocardiographic and radionuclide measurements.

OBJECTIVE: The aim of the study was to validate a previously published method to calculate left ventricular ejection fraction (EF) from the myocardial performance index (MPI or Tei-index) in patients with acute myocardial infarction (MI). METHODS: Sixty-one patients in sinus rhythm without overt heart failure were examined between 2 and 7 days after the acute MI. Doppler tracings from mitral inflow and left ventricular outflow were recorded together with two-dimensional echocardiographic (2DE) recordings. MPI was calculated from the Doppler tracings, and EF measured with the biplane Simpson's method. From MPI the EF was calculated by the formula EF = 0.60 - (0.34 x MPI). Radionuclide angiographic (RNA) measurements of EF were performed within 1 day of the Doppler echocardiography. RESULTS: Compared with radionuclide EF, MPI derived EF significantly underestimated EF by 0.03 (+/-0.013; P = 0.027), whereas there was no significant difference in mean EF between 2DE and RNA. There was no statistically significant difference in the agreement between MPI derived EF relative to RNA, or 2DE relative to RNA. The agreement between the three methods was only moderate with wide limits of agreement (+/-0.17). The relationship expressed by the proposed formula for calculating EF from MPI was not statistically significant in regression analysis in this patient population. CONCLUSIONS: No statistically significant relationship was found between MPI and EF by radionuclide angiography. However, MPI derived EF was as accurate as biplane echocardiographic measurements of EF when compared with radionuclide EF, but the agreement between methods was only moderate.

Echocardiography, Doppler↗

PubMed2001

Relevance of 99mTc-MIBI rest uptake, ejection fraction and location of contractile abnormality in predicting myocardial recovery after revascularization.

The aim of this study was to analyse the influence of rest technetium-99m-methoxy-isobutyl-isonitrile (99mTc-MIBI) uptake, left ventricular ejection fraction (EF) and dysfunctional location in the prediction of myocardial viability. Rest 99mTc-MIBI single photon emission computed tomography (SPECT) was analysed in 82 patients (59+/-9 years, 70 men, 12 women) with one or more segments showing severe hypokinesia, akinesia or dyskinesia who had undergone coronary revascularization. Before and within 3-6 months after the revascularization, gated blood pool scintigraphy was performed. In the post-revascularization control, contractile recovery was observed in 48.7% (155/318) of the segments with severe hypokinesia, akinesia or dyskinesia. Significant increases in sensitivity (53%, 72% and 91%, P<0.0001) and negative predictive value (62%, 68% and 79%, P = 0.01) were observed with decreasing rest uptake 99mTc-MIBI levels of 50%, 40% and 30%, respectively. The decrease in specificity was also significant (67%, 53% and 32%, P<0.0001). The negative predictive value was higher than the positive predictive value mainly in patients with EF < or = 0.35 and with anterior dysfunction. In logistic regression analysis, uptake levels and EF were independent variables that influenced sensitivity and specificity. The negative predictive value was influenced by EF and the positive predictive value only by dysfunctional location. This study suggests that the negative predictive value of 99mTc-MIBI SPECT is higher than the positive predictive value, mainly in patients with EF < or = 0.35, and that the rest uptake level, EF and dysfunctional location are factors that must be considered when results of 99mTc-MIBI SPECT are analysed.

Aged↗

PubMed2004

Assessment of cardiac wall motion and ejection fraction with gated PET using N-13 ammonia.

BACKGROUND: Cardiac gating is not routinely used in cardiac positron emission tomography (PET). The aim of this study was to determine the feasibility of assessing regional wall motion, ejection fraction (EF), cardiac volumes, and mass with nitrogen-13 ammonia (N-13 ammonia) at the time of PET myocardial perfusion imaging. METHODS: We studied 12 healthy volunteers (mean age, 28 +/- 8 years) and 53 patients with documented coronary artery disease (CAD) (mean age, 59 +/- 11 years). All subjects received a single administration of approximately 600 MBq (16 mCi) of N-13 ammonia intravenously. A 6-minute dynamic scan was performed for quantitative assessment of myocardial perfusion at rest, followed by a separate, 13-minute static scan acquired in the gated mode (8 equal bins). Gated data was imported into the Emory Toolbox. Wall motion was evaluated by dividing the myocardium into 9 anatomic regions graded semiquantitatively. RESULTS: Healthy volunteers had a normal EF (61 +/- 6), end systolic volume (ESV) (37 +/- 15 mL), end diastolic volume (EDV) (89 +/- 25 mL), and cardiac mass (116 +/- 18 g). In contrast, patients with CAD showed reduced EF (32 +/- 13%) and increased ESV (129 +/- 56 mL), EDV (188 +/- 68 mL), and cardiac mass (173 +/- 45 g) (P < 0.001 for each). In patients with CAD, EF measured by gated PET correlated significantly to independent measurements of EF (P < 0.001). CONCLUSIONS: Gating of cardiac perfusion images obtained after administration of N-13 ammonia is feasible and appears to be an accurate means of evaluating regional and global cardiac function. Gating can provide important additional diagnostic and prognostic information.

Adult↗

PubMed1992

Influence of age on the relation between heart rate variability, left ventricular ejection fraction, frequency of ventricular extrasystoles, and sudden death after myocardial infarction.

AIMS: To examine the influence of age on the prediction of sudden death after acute myocardial infarction based on heart rate variability (HRv), left ventricular ejection fraction (LVEF), and the frequency of ventricular extrasystoles. BACKGROUND: Autonomic and left ventricular function and the frequency of ventricular extrasystoles change with age but the influence of age on the prediction of sudden death from these variables has not been examined. METHODS: The 477 patients who had been through an early postinfarction risk stratification protocol and followed up for a mean of 790 days were dichotomised at 60 years of age. RESULTS: Sudden deaths occurred with similar frequency in both age groups (12 (4.7%) of the 256 patients aged < 60 years and seven (3.2%) of the 221 older patients). Sudden death, however, accounted for 52% of all deaths in the young group but only 18.4% of all deaths in the older group (p < 0.01). An HRv index of < 20 units combined with an average of more than 10 ventricular extrasystoles an hour on Holter monitoring (VE10) had a sensitivity of 50%, a positive predictive accuracy of 33%, and a risk ratio of 18 in the young group (p < 0.001) but was not significantly predictive in older patients. The situation was similar when the combination of an LVEF < 40% with VE10 was considered. This combination had a sensitivity of 44%, positive predictive accuracy of 36.4%, and a risk ratio of 16.1 in young patients (p < 0.001), but was not significantly predictive in older patients. The combination of VE10 with either LVEF < 40% or HRv < 20 units gave a sensitivity of 75%, positive predictive accuracy of 30%, and a risk ratio of 30 in young patients (p < 0.001), but the relation between this combination and sudden death in older patients was not statistically significant. CONCLUSION: In postinfarction patients aged < 60 sudden death was a more predominant mode of death and was more reliably predicted from a depressed HRv index, an LVEF < 40%, and VE10 than in older postinfarction patients. These findings may have important implications for post-infarction risk stratification and management.

Age Factors↗