Left ventricular performance in coronary artery disease evaluated with systolic time intervals and echocardiography

The Relationship Between Global Left Ventricular Function, as Indicated by the Tei Index, and Long-Term Survival in Patients With Non-Ischemic, Dilated Cardiomyopathy

AIM

Idiopathic dilated cardiomyopathy (DCM) is one of the leading causes of low ejection fraction (EF) heart failure (HF). The Tei index is a reliable marker that reflects both left ventricular (LV) systolic and diastolic function, and it has prognostic value in patients with DCM. We aimed to investigate the relationship between the Tei index and long-term survival in non-ischemic, DCM patients.

MATERIAL AND METHODS

The present study included 98 patients with non-ischemic DCM. The mean survival time of the patients was 59 mos.

RESULTS

The Tei index was prominently higher in patients who died (0.64±0.08 vs 0.71±0.12, respectively; p=0.01). LV end-systolic volume and LV ejection fraction (LVEF) were independent prognostic factors and predicted worse long-term survival. Additionally, the patients with LVEF ≥32.7 % and the Tei index ≤0.76 had significantly longer survival.

CONCLUSION

The present study showed that the Tei index was significantly associated with mortality and the patients with both low LVEF (≤32.7 %) and high Tei index (≥0.76) values had a shorter life expectancy. As a result, we suggest that the Tei index may be a useful echocardiographic marker to predict long-term survival in DCM patients.

Age related structural and functional changes in left ventricular performance in healthy subjects: a 2D echocardiographic study

Left ventricular (LV) adaptation to aging is currently poorly understood. We aimed to characterize age related changes in LV structure and function by studying a large group of healthy subjects across a wide age range. Prospectively enrolled healthy volunteers (n = 778, 327 females; age 18 to 100 years, mean age 49.8 ± 18.1 years), were divided into 4 age groups: 18 to 34 years (n = 165); 35 to 49 years (n = 242), 50 to 79 years (n = 334) and ≥ 80 years (n = 40). All subjects underwent clinical examination, as well as comprehensive transthoracic echocardiogram [TTE]. Body mass index, systolic blood pressure (BP), and left atrial volume (p < 0.0001) increased with age while diastolic BP (p < 0.0001) decreased over time. LV mass/body surface area (BSA) and relative wall thickness increased with age (p < 0.0001) coincident with worsening parameters of diastolic function (E/A and E/Em, p < 0.0001). The ejection fraction and Sm did not change significantly. Stroke volume, ejection time index, flow rate and stroke work significantly increased with age (p < 0.01). The arterial elastance (Ea), a measure of ventricular afterload, and ventricular elastance (Ees), an index of LV systolic stiffness did not change with age nor did their ratio (Ees/Ea) the latter being an expression of ventricular-arterial coupling. Age, gender and LVM were the main independent variables associated with LV systolic function. In conclusion, LV adaptation to aging in a healthy cohort is characterized by concentric LV remodeling, increased contractility and preserved ventricular-arterial coupling.

Tissue doppler myocardial performance index in patients with heart failure and its relationship with haemodynamic parameters

The myocardial performance index (MPI) reflects both the systolic and diastolic function of the heart, and is easily applied in practice. In this study, we aimed to determine the relationship between MPI and invasive haemodynamic parameters in heart failure patients. A total of 126 patients with heart failure were selected, all of whom were referred for diagnostic cardiac catheterisation, and were divided into two groups. Group I consisted of 59 patients (32 men and 27 women, mean age 61 ± 10; functional capacity New York Heart Association (NYHA) Class I; and left ventricular end-diastolic pressure (LVEDP) <16 mmHg). Group II included 67 patients (34 men and 33 women, mean age 60 ± 9; NYHA Class ≥ II; LVEDP ≥ 16 mmHg). The following parameters were measured in all patients: ejection fraction with Simpson method, the peak mitral early (E) and late (A) diastolic velocities, E/A ratio, deceleration time (DT) and tissue Doppler from four different areas of the mitral annulus (septum, lateral, inferior and anterior). In order to measure MPI with two methods (standard Doppler and tissue Doppler), isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT) and ejection time (ET) were measured from four areas and mean values of MPI were calculated. There was no difference between the two groups in E/A ratios, DT and IVRT (p > 0.05). Group II patients had longer IVCT and ET, when compared with group I patients (p < 0.05). MPI, measured by both standard pulsed wave Doppler and tissue Doppler methods, was significantly higher in group II patients, when compared with the values obtained from group I patients (Group I: 0.50 ± 0.2 and 0.50 ± 0.14; group II: 0.98 ± 0.3 and 1.2 ± 0.32; p < 0.001). According to receiver operating characteristics curve analysis, the cut-off value for MPI measured by tissue Doppler was 0.74. The sensitivity and specificity of this value were measured as 92.5 and 91.5%, respectively. MPI measured by standard Doppler method was 0.67, and its sensitivity and specificity were 85.1 and 83.1%, respectively. We found a strong relationship between MPI and LVEDP (r = 0.83, p < 0.001; r = 0.96, p < 0.001), especially when measured by tissue Doppler. In addition, we observed a significant relationship between the MPI values measured by tissue Doppler and those measured by standard traditional methods (r = 0.85, p < 0.001). We showed that MPI was reliable for the evaluation of global cardiac functions in patients with heart failure, as measured with both pulsed-wave Doppler and tissue Doppler. We assert that, in order to differentiate between those patients with symptomatic heart failure from the asymptomatic cases, MPI as measured with the tissue Doppler method is an improvement on MPI as measured using traditional methods.

U-shaped relationship of left ventricular ejection time index and all-cause mortality

BACKGROUND

Previous studies have suggested that systolic and diastolic heart failure is associated with alterations of left ventricular ejection time index (LVETI). We sought to examine the relation of LVETI to mortality in an elderly population.

METHODS

We prospectively enrolled 852 patients undergoing cardiac catheterization for suspected coronary artery disease (CAD) in 2001 and 2002. LVETI was measured noninvasively using radial applantation tonometry and pulse waveform analysis. Mortality data were assessed by telephone interviews with general practitioners, hospital records, and the national mortality register.

RESULTS

The mean age was 64.8 years, 60.7% of subjects were men, 70.1% of subjects had significant CAD, and 28.6% of subjects had impaired systolic function. After a mean follow-up of 8.2 ± 2.3 years, 183 deaths occurred. At baseline, LVETI was significantly associated with age, systolic and diastolic blood pressure, pulse pressure, and N-terminal probrain natriuretic peptide. A shorter LVETI was significantly and independently associated with impaired systolic function. Kaplan-Meier analysis revealed that both prolonged and shortened ejection time index (1st and 3rd tertile LVETI) were associated with a decreased survival probability (P <0.05, log-rank-test) compared with normal LVETI (2nd tertile). In multivariable Cox regression analysis, the hazard ratios for all-cause mortality were 1.66 for 1st tertile LVETI (P = 0.01) and 1.75 for 3rd tertile LVETI (P = 0.006). The effect of a shortened LVETI on mortality was partly due to the effect of impaired systolic function on ejection duration.

CONCLUSIONS

We observed a U-shaped relation between ejection duration and all-cause mortality.

Left ventricular function after myocardial infarction: relation between systolic time intervals and quantitative ischaemic ECG changes

Twentyfour male patients with sustained myocardial infarction (MI) were studied with 12-lead ECG and systolic time intervals (STI) 5 months after the acute episode. From the ECGs were calculated the summed voltages of the R wave (sigma R), the Q wave (sigma Q), and the ST segment deviation (sigma ST). These ischaemic ECG variables were correlated with the STI parameters of left ventricular function: LVETI, PEP and PEP/LVET. Statistically significant regression equations relating the ECG changes to the STI variables were found in anterior MI, for sigma ST in the entire series, but not in inferior MI. Thus a simple and rapid inspection of the resting 12-lead ECG gives an indirect but reliable quantitative estimate of left ventricular function in patients with a sustained myocardial infarction.

Right ventricular dysfunction in hypertrophic cardiomyopathy as evidenced by the myocardial performance index

BACKGROUND

Left ventricular function in hypertrophic cardiomyopathy (HCM) has been extensively studied, whereas right ventricular function is much less explored. The myocardial performance index (MPI) has been shown to be useful in functional assessment of both ventricles. Furthermore, right ventricular MPI was found to be of predictive value in heart failure due to dilated cardiomyopathy and ischemic heart disease. The aim of this study was, therefore, to evaluate the right ventricular MPI in patients with HCM.

METHODS

Fifty patients with HCM and 250 healthy controls were studied by conventional Doppler echocardiography and Doppler tissue imaging.

RESULTS

Patients showed increased global, 0.48 (0.15) vs. 0.21 (0.14), and regional, 0.71 (0.23) vs. 0.55 (0.17), right ventricular MPI, as compared to controls, p<0.001. Tricuspid annular plane systolic excursion and peak myocardial systolic velocities were also reduced. Patients with dyspnoea had increased global right ventricular MPI (0.53 vs. 0.36, p<0.05) as compared to those without dyspnoea.

CONCLUSION

In the present study, patients with HCM showed evidence of both global and regional right ventricular dysfunction. Previous studies of the right ventricle in HCM have only shown evidence of diastolic dysfunction, contrary to our results, showing impairment of both systolic and diastolic function. This study suggests that HCM should not only be regarded as an isolated disease of the left ventricle, but rather as a biventricular disease. The predictive value of our findings in HCM needs to be assessed in a separate study with special reference to those with and without dyspnoea.

Performance of phonoelectrocardiographic left ventricular systolic time intervals and B-type natriuretic peptide levels in the diagnosis of left ventricular dysfunction

BACKGROUND

Systolic time intervals measured by echocardiography and carotid artery tracings are validated methods of assessing left ventricular function. However, the clinical utility of phonoelectrocardiographic systolic time intervals for predicting heart failure using newer technology has not been evaluated.

METHODS

We enrolled 100 adult patients undergoing left heart catheterization. Participants underwent computerized phonoelectrocardiographic analysis, left ventricular end-diastolic pressure (LVEDP) measurement, transthoracic echocardiographic measurement of left ventricular ejection fraction (LVEF), and B-type natriuretic peptide (BNP) testing. The heart rate-adjusted systolic time intervals included the time from the Q wave onset to peak S1 (electromechanical activation time, EMAT), Q wave onset to peak S2 (electromechanical systole, Q-S2), and peak S1 to peak S2 (left ventricular systolic time, LVST). Left ventricular dysfunction was defined as the presence of both LVEDP >15 mmHg and LVEF <50%.

RESULTS

EMAT (r =-0.51; P < 0.0001), EMAT/LVST (r =-0.41; P = 0.0001), and Q-S2 (r =-0.39; P = 0.0003) correlated with LVEF, but not with LVEDP. An abnormal EMAT > or =15 (odds ratio 1.38, P < 0.0001) and EMAT/LVST > or =0.40 (OR 1.13, P = 0.002) were associated with left ventricular dysfunction. EMAT > or =15 had 44% sensitivity, 94% specificity, and a 7.0 likelihood ratio for left ventricular dysfunction, while EMAT/LVST > or =0.40 had 55% sensitivity, 95% specificity, and a 11.7 likelihood ratio. In patients with an intermediate BNP (100-500 pg/mL), the likelihood ratio increased from 1.1 using the BNP result alone to 11.0 when adding a positive EMAT test for predicting left ventricular dysfunction.

CONCLUSIONS

Phonoelectrocardiographic measures of systolic time intervals are insensitive but highly specific tests for detecting abnormalities in objective markers of left ventricular function. EMAT and EMAT/LVST provide diagnostic information independent of BNP for detecting patients with left ventricular dysfunction.

Diagnostic characteristics of combining phonocardiographic third heart sound and systolic time intervals for the prediction of left ventricular dysfunction

BACKGROUND

The third heart sound (S3) and systolic time intervals (STIs) are validated clinical indicators of left ventricular (LV) dysfunction. We investigated the test characteristics of a combined score summarizing S3 and STI results for predicting LV dysfunction.

METHODS AND RESULTS

A total of 81 adults underwent computerized phonelectrocardiography for S3 and STI (Audicor, Inovise Medical Inc), cardiac catheterization for LV end-diastolic pressure (LVEDP), echocardiography for LV ejection fraction (LVEF), and B-type natriuretic peptide (BNP) testing. LV dysfunction was defined as both an LVEDP >15 mm Hg and LVEF <50%. The STI measured was the electromechanical activation time (EMAT) divided by LV systolic time (LVST). Z-scores for the S3 confidence score and EMAT/LVST were summed to generate the LV dysfunction index. The LV dysfunction index had a correlation coefficient of 0.38 for LVEDP (P = .0003), -0.53 for LVEF (P < .0001), and 0.35 for BNP (P = .0008). This index had a receiver operative curve c-statistic of 0.89 for diagnosis of LV dysfunction; a cutoff >1.87 yielded 72% sensitivity, 92% specificity, 9.0 positive likelihood ratio, and 88% accuracy.

CONCLUSIONS

In this preliminary study, the LV dysfunction index combined S3 and STI data from noninvasive electrophonocardiography, and yielded superior test characteristics compared to the individual tests for the diagnosis of LV dysfunction.

Effects of afterload increase on systolic and diastolic functions of the myocardium after myocardial infarction

The evaluation of noninfarcted zone function after myocardial infarction by the use of noninvasive methods is very important. The authors speculated that phenylephrine, which increases systemic vascular resistance and blood pressure and has no effect on central ischemic and border-zone myocardium but does have an effect on remote myocardium, could be used as a stress agent as information is gathered about the functional capacity of the left ventricle and the status of coronary arteries in patients with recent myocardial infarction. Forty-six patients with recent myocardial infarction (5 women, 41 men; mean age: 53.6 +/-9.3 years) and 15 individuals with normal findings from coronary angiography and ventriculography (9 women and 6 men; mean age: 39.0 +/-11.2 years) were included in the study. The study was performed on the 4th or 5th day of the myocardial infarction. Preejection period/left ventricular ejection time (PEP/LVET), diastolic mitral flow velocity, isovolumic relaxation time (IVRT), and deceleration time (DT), were measured before and after the phenylephrine infusion, with M-mode, pulse wave, and continuous-wave echocardiography. After pressor stress with phenylephrine infusion, all the parameters were measured again. Coronary angiography and ventriculography were performed on all the patients on the 7th to 10th day of the myocardial infarction. All the patients were grouped according to their ejection fraction and the number of involved coronary arteries. The increase in the PEP/LVET ratio in Group 1 (left ventricle ejection fraction [EF] below 40%) and multivessel coronary artery lesion group was significant (p<0.01). PEP/LVET ratio decreased significantly in both Group C (patients with normal-appearing coronary arteries and ventriculographies) and the single-vessel coronary disease group. Although the early diastole flow/atrial systole flow (E/A) ratio increased significantly in the 3 groups, the 0.5 and more increase in E/A ratio had high sensitivity (86%) and specificity (80%) in differentiating the low EF group. The 0.5 and more increase in E/A ratio had 65% sensitivity and 69% specificity in differentiating the multivessel coronary stenosis group. A deceleration time of 130 msec and below in basal conditions had a high sensitivity (86%) and specificity (92%) for detecting the group in which EF was below 40%. After phenylephrine infusion, the shortening of IVRT was significant in Group 1 (p<0.01). Phenylephrine, which has been shown to be an alpha-1 receptor agonist in low doses and effective only on remote myocardial function, may be given with low complication rates in the early postinfarction period. The increase in PEP/LVET ratio, 0.5 and more increase in E/A ratio, and shortening of DT and IVRT after phenylephrine infusion may be indicators of low LV functional capacity and widespread coronary artery disease. This test may suggest performance of early invasive detection of coronary artery disease and early revascularization. This study may also be interesting from a pathophysiological point of view.

Prognostic Value of Global Myocardial Performance Indices in Acute Myocardial Infarction *

STUDY OBJECTIVES

Assessment of global myocardial performance by a single index (ie, the myocardial performance index [MPI]) has been suggested as an appealing alternative to the individual assessment of systolic and diastolic left ventricular (LV) function We sought to test the prognostic value of MPI in comparison to clinical characteristics and echocardiographic parameters of LV filling and ejection in acute myocardial infarction (AMI).

PATIENTS

Four hundred seventeen consecutive patients with AMI were examined within 24 h of hospital admission.

INTERVENTIONS

Doppler echocardiographic measures of systolic, diastolic, and global myocardial performance were assessed within 24 h of hospital admission. In addition to MPI (ie, the sum of the isovolumic time intervals divided by ejection time), we determined the isovolumic/heterovolumic time ratio, which expresses the time "wasted" by the myocardium to generate and decrease LV pressure without moving blood.

RESULTS

The end points of the study at 30 days were death (4.7%), congestive heart failure (23%), and recurrent infarction (4.8%), and occurred in 109 patients, who were compared as group B to 314 patients without an event (group A). Multivariate analysis identified only age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.07), LV ejection fraction (LVEF) < or = 40% (OR, 3.82; 95% CI, 2.15 to 6.87), and E-wave deceleration time (EDT) of < or = 130 ms (OR, 2.29; 95% CI, 1.0 to 5.21) as independent predictors of adverse events.

CONCLUSION

LVEF and EDT are powerful and independent echocardiographic predictors of poor outcome following AMI, and are superior to indexes of global LV performance. Both parameters should be taken into consideration when deciding about the management of these patients.

Novel approach to measure myocardial performance index: pulsed-wave tissue Doppler echocardiography

A simple, reproducible, noninvasive myocardial performance index (MPI) for the assessment of overall cardiac function has been described previously. The purpose of this study was to compare the MPI obtained by pulse Doppler method with the MPI obtained by tissue Doppler echocardiography (TDE) in normal subjects and patients with dilated cardiomyopathy (DCMP). Fifteen patients with DCMP and 15 healthy subjects were included. In order to calculate MPI by TDE, isovolumetric contraction (IVCT), relaxation time (IVRT), and ejection time (ET) were measured at two different sites of mitral annulus: septum and lateral. MPI was calculated by dividing the sum of IVCT and IVRT by ET at each site of measurement. The mean MPI value was found by dividing the sum of these MPI values into two. The same parameters were measured using the mitral inflow and left ventricular outflow velocity time intervals in pulsed Doppler method. At all sites measured, MPI by TDE correlated well with conventional MPI both in healthy subjects and patients with DCMP. The highest correlation was observed in mean values of MPI by TDE:r = 0.94, P < 0.0001in healthy subjects; andr = 0.95, P < 0.0001in patients with DCMP. In conclusion, this study clearly demonstrated that MPI could be measured by TDE and it correlated well with conventional MPI in normal and diseased heart.

Severe aortic valve stenosis with preserved and reduced systolic left ventricular function: diagnostic usefulness of the Tei index

BACKGROUND

In patients with severe aortic valve stenosis (AS), the onset of heart failure is associated with increased mortality and higher operative risk. Heart failure may result from either systolic, diastolic, or "overall" left ventricular dysfunction. The index "isovolumic contraction time and isovolumic relaxation time divided by ejection time" was shown to be a sensitive indicator of "overall" cardiac dysfunction in patients with dilated cardiomyopathy and cardiac amyloidosis. We sought to define the role of the Tei index in patients with severe AS and to validate this index against conventional measures of systolic and diastolic LV function.

PATIENTS AND METHODS

Fifty-three participants underwent left heart catheterization for invasive measurement of LV end-diastolic pressure as a marker of diastolic function: 10 AS patients (valve orifice 0.6 +/- 0.2 qcm) with depressed systolic LV function (defined by LV ejection fraction < or = 45% [mean 32% +/- 8%], 7 male/3 female, 72 +/- 10 years old, DAS group), 22 AS patients (valve orifice 0.7 +/- 0.2 qcm) with preserved systolic LV function (ejection fraction > 45% [mean 55% +/- 6%], 13 male/9 female, 71 +/- 11 years old, PAS group) and 21 asymptomatic control participants (ejection fraction > 45% [mean 62% +/- 8%], 14 male/7 female, 66 +/- 8 years old, CON group). Within 24 hours from catheterization, conventional 2-dimensional and Doppler echocardiographic examination including measurement of the Tei index was performed.

RESULTS

LV end-diastolic pressure was elevated in the DAS and in the PAS group in comparison with control participants (32 +/- 6 mm Hg and 22 +/- 7 mm Hg vs 11 +/- 4 mm Hg, respectively, P <.01 for both comparisons). DAS patients were in a higher New York Heart Association functional class than PAS patients (3.2 +/- 0.4 vs 2.2 +/- 0.4, P <.001) The Tei index was easily and reproducibly obtained in all study participants. In the DAS group, isovolumic contraction time was prolonged and ejection time was shortened in comparison with the CON group (102 +/- 20 ms vs 52 +/- 15 ms, P <.01; and 235 +/- 44 ms vs 316 +/- 45 ms, P <.01), resulting in a significantly increased Tei index (0.78 +/- 0.28 vs 0.40 +/- 0.11, P <.01). In the PAS group, isovolumic relaxation time was shortened (62 +/- 18 ms vs 81 +/- 26 ms for the CON group, P <.01) and ejection time was prolonged (335 +/- 34 ms vs 316 +/- 45 ms for the CON group, P <.05), resulting in a decreased Tei index (0.29 +/- 0.12 vs 0.40 +/- 0.11, P <.05). Receiver operating characteristic curve analysis for the Tei index yielded an area under the curve of 0.98 +/- 0.03 for separating DAS and PAS patients. Using a Tei index greater than 0.42 as a cutoff, DAS patients were identified with a sensitivity of 100% and a specificity of 91%.

CONCLUSION

The Tei index is significantly increased in patients with severe AS and depressed overall cardiac LV function. In AS patients with predominant diastolic dysfunction, in whom systolic function is preserved, the index is decreased in comparison with control patients. The index differentiates between symptomatic AS patients with depressed and less symptomatic AS patients with preserved systolic LV function, and may thus provide relevant information in the work-up and care of such patients.

Left ventricular dysfunction after long-term right ventricular apical pacing in the young

OBJECTIVES

The goal of this study was to assess long-term global left ventricular (LV) function in patients paced from the right ventricular (RV) apex at a young age.

BACKGROUND

Ventricular contraction asynchrony with short-term RV apical pacing has been associated with reduced LV pump function and relaxation. The long-term effect of RV apical pacing on global LV function in the young remains unknown.

METHODS

Twenty-four patients with normal segmental anatomy paced from the RV apex (follow-up 1 to 19 years) underwent noninvasive assessment of global LV function with automated border detection echocardiography-derived fractional area of change (FAC), coupled with the Doppler index of myocardial performance (MPI). Data were analyzed from 24 RV-paced patients (mean follow-up 9.5 years, age 19 years, body surface area [BSA] 1.6 m2, QRS duration 140 ms) and compared with 33 age- and BSA-matched control subjects (age 16.4 years, BSA 1.6 m2). Multiple linear regression analysis was performed to identify patient variables that can affect these indexes of LV function.

RESULTS

Assessment of LV function (median follow-up 10 years) in 24 paced patients demonstrated impaired area- and Doppler flow-derived indexes of LV systolic and diastolic function, compared with those indexes of control subjects (FAC: 52% vs. 60%, p < 0.01; MPI: 0.46 vs. 0.34, p < 0.01). Paced QRS interval and age were found to significantly influence global LV contraction in these patients (R2 = 0.4, p < 0.05).

CONCLUSIONS

In the presence of impaired LV function with long-term RV apical pacing, alternative sites of ventricular pacing that simulate normal biventricular electrical activation should be explored to preserve function in pediatric patients in need of long-term pacing.

Value of the Doppler index of myocardial performance in the early phase of acute myocardial infarction

Prospective assessment of a nongeometric Doppler-derived index of combined systolic and diastolic myocardial performance was performed in 64 patients with acute myocardial infarction (MI) within 1 hour after their arrival to the hospital and in 39 age-matched healthy subjects. The index is defined as the sum of isovolumetric contraction time and relaxation time divided by ejection time, and is obtained by Doppler measurement from the mitral inflow and left ventricular outflow velocity-time intervals. The index was significantly higher in patients with MI compared with healthy subjects (P <.0001). In patients with MI and in-hospital congestive heart failure (CHF), the index was significantly higher compared with patients without CHF. In a multivariate regression analysis, the index >0.45 was the strongest independent predictor of the development of CHF. This simply obtained nongeometric Doppler index, assessed in the early phase of MI, detected and graded left ventricular dysfunction and identified patients at risk for the development of CHF.

Estimation of the ejection fraction in patients with myocardial infarction obtained from the combined index of systolic and diastolic left ventricular function: a new method

The index of myocardial performance combining systolic and diastolic time intervals (Index) is a useful method, already explained in past studies, that offers new values that have not been widely known among clinical cardiologists. The aim of this study is to obtain from this Index a measurement of the ejection fraction (EF), which is a very well-known value. The study involved 97 patients with myocardial infarction, 55 of whom were studied retrospectively (group A, aged 46-62 years, 50 men) to obtain and test the formula EF = 60 - (34 x Index). The second group (group B, aged 47-63 years, 40 men) included 42 patients who were evaluated prospectively. The EF obtained was compared with that reached through the use of radionuclide angiography (EF-RNA). The Index was obtained through the use of the formula (a - b)/b, where a is the interval between cessation and onset of the mitral inflow, and b is the ejection time. In group A the EF obtained by the Index (EF-Index) was 37.5% +/-.8%, and the EF-RNA was 37.7% +/- 11% (r = 0.76). In group B the EF-Index was 41.6% +/- 7%, and the EF-RNA was 41.2% +/- 10% (r = 0. 75).

CONCLUSION

Through the new formula described here it is possible to obtain a reliable measurement of the EF in patients with myocardial infarction, a well-known and extremely useful value, especially for those patients with poor acoustic windows.

Serial changes and prognostic implications of a Doppler-derived index of combined left ventricular systolic and diastolic myocardial performance in acute myocardial infarction

The purpose of this study was to investigate the serial changes and prognostic value of a nongeometric Doppler-derived index of myocardial function that combines systolic and diastolic time intervals of the left ventricle in acute myocardial infarction (AMI). The Doppler index was measured in 60 consecutive patients with AMI and in 30 patients admitted to hospital with suspected but disproved AMI who served as controls. The patients were studied at days 1, 5, 90, and 360 after arrival in the coronary care unit. The index was defined as the sum of isovolumetric contraction time, and isovolumetric relaxation time divided by ejection time was measured from mitral inflow and left ventricular outflow Doppler velocity profiles. The index was significantly higher in patients with AMI than in control subjects at days 1 and 360 (day 1, 0.58 +/- 0.09 vs 0.41 +/- 0.08, p <0.0001; day 360, 0.50 +/- 0.09 vs 0.39 +/- 0.07, p <0.01, respectively). The index decreased significantly in patients with AMI during follow-up (p <0.01). The index was significantly higher in patients who developed congestive heart failure or died compared with survivors who were free of congestive heart failure (day 1, 0.63 +/- 0.10 vs 0.53 +/- 0.10, p <0.01; day 360, 0.56 +/- 0.08 vs 0.48 +/- 0.10, p <0.01, respectively). During 20.2 +/- 8.5 months' follow-up, 10 patients died of cardiac causes and 13 developed congestive heart failure. Univariate analyses demonstrated that the Doppler index > or =0.60 (chi-square 8.3, p <0.0001), deceleration time < or =140 ms (chi-square 8.5, p <0.0001), ejection fraction < or =0.40% (chi-square 3.3, p <0.005), anterior wall AMI (chi-square 3.2, p <0.01), and age (chi-square 1.06/ year increase, p <0.01) were significant predictors of outcome. Multivariate stepwise analysis showed that the index < or =0.60 (chi-square 3.4, p <0.05), deceleration time < or =140 ms (chi-square 4.2, p <0.02), and age (chi-square 1.06/year increase, p <0.02) were independent predictors of outcome. The Doppler index reflects severity of left ventricular function and has incremental prognostic value in patients with AMI.

Noninvasive Doppler-derived myocardial performance index: correlation with simultaneous measurements of cardiac catheterization measurements

A simple, reproducible, noninvasive Doppler index for the assessment of overall cardiac function has been described previously. The purpose of this study was to correlate the Doppler index with accepted indexes of cardiac catheterization of left ventricular performance. Thirty-four patients with ischemic heart disease or idiopathic dilated cardiomyopathy prospectively underwent a simultaneous cardiac catheterization and Doppler echocardiographic study. Invasive measurements of peak +dP/dt, peak -dP/dt, and tau were obtained from the high-fidelity left ventricular pressures. A Doppler index of myocardial performance was defined as the summation of isovolumetric contraction and relaxation time divided by ejection time. There was a correlation between Doppler measurement of isovolumetric contraction time and peak +dP/dt (r = 0.842; p < 0.0001) and Doppler measurement of isovolumetric relaxation time and peak -dP/dt (r = 0.638; p < 0.001). Left ventricular ejection time correlated with both peak +dP/dt (r = 0.539; p < 0.001) and peak -dP/dt (r = 0.582; p < 0.001). The Doppler index correlated with simultaneously recorded systolic peak +dP/dt (r = 0.821; p < 0.0001) and diastolic peak -dP/dt (r = 0.833; p < 0.001) and tau (r = 0.680; p < 0.0001). This study documents that a simple, easily recordable, noninvasive Doppler index of myocardial performance correlates with invasive measurement of left ventricular systolic and diastolic function and appears to be a promising noninvasive measurement of overall cardiac function.

Systolic time intervals after phenylephrine administration for early stratification of patients after acute myocardial infarction

This study was designed to assess the usefulness of the changes in left ventricular (LV) systolic time intervals after phenylephrine administration for detecting high-risk patients soon after acute myocardial infarction by correlation with the angiographic and ventriculographic findings. The procedure was performed in 76 consecutive patients (group I) on the fourth postinfarction day and in 12 normal subjects (group II) free of coronary artery disease. In 20 patients with LV ejection fraction < or = 40% (subgroup IA) the preejection period (PEP)/LV ejection time (ET) ratio increased from 0.410 +/- 0.107 to 0.535 +/- 0.102 (p = 0.01) after phenylephrine, whereas in the remaining 56 patients (subgroup IB) with LV ejection fraction > 40% and in the 12 normal subjects the PEP/LVET increased nonsignificantly. Of patients with LV ejection fraction > 40% a subset of 20 patients was distinguished with proximal stenosis in both left anterior descending and either a dominant right or left circumflex coronary artery (subset IB-a). In these the PEP/LVET increased from 0.347 +/- 0.056 to 0.445 +/- 0.019 (p = 0.0001) after phenylephrine, whereas in the remaining 36 patients (subset IB-b) without proximal lesions in 2 main arteries the PEP/LVET increased nonsignificantly. In conclusion, the PEP/LVET response to phenylephrine administration early after acute myocardial infarction is a precise, safe, noninvasive bedside method for early stratification of these patients.

Effect of prolonged intense endurance training on systolic time intervals in patients with coronary artery disease

We studied the effect of exercise training (ET) on systolic time intervals (STI) in 13 patients with coronary artery disease (CAD). All patients trained for at least 10 months. They exercised three times/week at 50% to 70% of maximal oxygen uptake (VO2max) for the initial 3 months and at least four times/week for approximately 50 minutes at 70% to 90% of VO2max thereafter. A significant training effect was documented by an increase in VO2max from 26.0 +/- 4.3 to 37.2 +/- 5.8 ml/kg/min (p less than 0.01), a lower heart rate (HR) at rest, and a lower blood pressure and HR during submaximal work. The indices of total electromechanical systole (QS2I) and left ventricular ejection time (LVETI) did not change. However, pre-ejection period index (PEPI) decreased from 137 +/- 9 msec to 129 +/- 9 msec (p less than 0.01). PEP/LVET decreased from 0.373 +/- 0.028 to 0.342 +/- 0.032 (p less than 0.01). Left ventricular end-diastolic dimension and posterior wall thickness, measured echocardiographically, were increased after training. We conclude that exercise training may improve myocardial performance in some patients with CAD.

Left ventricular dysfunction discriminated noninvasively beat by beat

To discriminate left ventricular (LV) dysfunctional beats noninvasively, simultaneous systolic time intervals (STI), acceleration ballistocardiograms (BCG) and respiratory cycle were recorded in 102 men with no history of cardiac disease and in 20 men with proved myocardial infarction or systemic hypertension. Thirty-six measurements were made on each heartbeat on a maximum of 20 beats per patient. The ratio of preejection period to LV ejection time (ET) varied significantly with the respiratory cycle in normal men, but not in men with proved myocardial infarctions or systemic hypertension. The BCG I-wave amplitude varied significantly with respiration in all 3 groups. Various statistical methods identified 9 primary variables of the 36, which differed significantly in a training group of 275 heartbeats in 19 normal, vs 46 beats in 5 coronary patients. A nonlinear quadratic discriminant function based on these primary variables identified 87% of the heartbeats as "normal" in the normal men and 98% as "coronary" in the coronary men. A test group of normal men older than 40 years showed 89% of 97 heartbeats "normal" and in hypertensive men 67% of 85 beats "normal." Comparison by patients showed a range of "coronary" beats in the training normal group from 0 to 50%, the older normal group 0 to 33%, and in the hypertensive patients 0 to 88%. The appropriate use of quadratic discriminant analysis to multivariable data may yield information not otherwise seen. A beat-by-beat identification of dysfunctional beats at rest may lead to a sensitive index that is prognostically useful.

Echocardiographic evaluation of left ventricular function

The ability of echocardiography to assess left ventricular function is entering an era of transition. Most existing data have been derived from M-mode measurements made along a single echo beam axis and, as such, were based on the assumption that the performance of the sampled segment represented that of the whole ventricle. The recent availability of two dimenensional echocardiography lessens the need to rely on this assumption.

Ventricular response to isometric and isotonic exercise. Echocardiographic assessment

The effects of supine isometric handgrip and graded isotonic bicycle ergometer exercise on left ventricular performance were studied echocardiographically in 20 normal subjects, aged 18 to 36. Measurements of the left ventricular minor axis diameter were taken from recordings performed at rest, during each form of exercise, and during recovery. At the completion of isometric exercise, the pressure-rate product increased significantly. There was no significant change in percentage of fractional shortening (%deltaD), while there was a small but significant fall in peak velocity of circumferential fibre shortening (peak Vcf). Isotonic exercise resulted in a significant increase in %deltaD and peak Vcf. The pressure-rate product also increased and showed a positive correlation with peak Vcf. Isotonic exercise produced a much greater stimulus to left ventricular contractility than isometric exercise and may be a useful means of detecting latent left ventricular dysfunction echocardiographically.

Percentage of shortening of the echocardiographic left ventricular dimension. Its use in determining ejection fraction and stroke volume

The percentage of shortening of the echocardiographic left ventricular dimension (% delta D) was prospectively evaluated in 42 patients without detectable asynergy during diagnostic cardiac catheterization and was found to correlate well with angiographic ejection fraction (r = 0.90). Ejection fraction was calculated as the product of % delta D X 1.7 or as % delta (D2), both formulae having similar degrees of accuracy and a better correlation with the angiographic determination than conventional formulae. Ejection fractions (angiographic and echocardiographic) of 51 percent or greater were always associated with a % delta D of 30 percent or more. In five patients the echocardiographically derived ejection fractions were normal (greater than or equal to 51 percent), while the angiographic ejection fractions were reduced; four of these patients had valvular regurgitation. End-diastolic volumes were calculated from end-diastolic echocardiographic dimensions utilizing a linear regression equation derived from correlating the end-diastolic echocardiographic dimension with the end-diastolic volume in 27 patients without valvular regurgitation (end-diastolic echocardiographic dimension ranged from 3.7 to 8.2 cm). The value for stroke volume determined as the product of calculated end-diastolic volume times ejection fraction correlated with the angiographically determined stroke volume (r = 0.88; standard error of estimate, +/- 11 ml) better than the value for stroke volume derived from conventional echocardiographic formulae.

Left ventricular performance in diabetic patients without clinical heart disease. Evaluation by systolic time intervals and echocardiography

To examine left ventricular performance in diabetic patients without clinical evidence of cardiac involvement, systolic time intervals (pre-ejection period, left ventricular ejection time index and ratio of pre-ejection period to left ventricular ejection time) and echocardiographic measures (percentage changes in minor axis diameter, end-diastolic and end-systolic diameter, end- diastolic volume and end-systolic volumes, stroke volume and ejection fraction), were obtained. There were 89 diabetic patients and 93 control subjects evaluated for systolic time intervals, and 40 diabetic patients and 20 control subjects evaluated by echocardiogram. The diabetic group demonstrated significant (P less than 0.001) differences from the normal control group in each of the noninvasive measures of systolic time intervals. Pre-ejection period/left ventricular ejection time ration was increased by 25 percent and the pre-ejection period was increased by 12 percent in the diabetic patients. Among 40 diabetic patients studied by echocardiography, abnormal percentage change in minor axis diameter, (less than 30 percent) occurred in six individuals. Ejection fraction was decreased by 20 percent as compared to the control group, whereas end-diastolic pressure was not significantly different in the groups.

Assessment of cardiac function in marathon runners by graphic noninvasive techniques

The volume overload type of heart often observed in endurance athletes, was simulate a diseased heart. We used a battery of noninvasive graphic techniques, i.e., echocardiogram, apexcardiogram, carotid pulse, electrocardiogram, vectorcardiogram, phonocardiogram, systolic time intervals, and treadmill stress testing in 12 professional marathon runners, mean age 33.8 +/- 11.1. Twenty nonathletes matched for age, height, sex, and weight served as a control group. Left ventricular (LV) end-diastolic dimension in marathon runners averaged 5.53 +/- 0.5 cm compared to 4.81 +/- 0.04 cm in nonathletes (p less than 0.001), LV end-diastolic volume was 172.69 +/- 43.3 ml compared to 113.57 +/- 30.41 ml in nonathletes (p less than 0.001), stroke volume was 122.27 +/- 32.8 ml compared to 78.42 +/- 20.44 ml in non-athletes (p less than 0.001), the thickness of the posterior LV wall was 1.0 +/- 0.2 cm compared to 0.7 +/- 0.1 cm in nonathletes (p less than 0.001), and LV mass was significantly increased, 212.43 +/- 55.8 g compared to 123.48 +/- 24.54 g in non-athletes (p less than 0.01). Left atrium and aortic root were also relatively larger in athletes (p less than 0.01). Right ventricular end-diastolic dimension was enlarged in marathon runners (2.02 +/- 0.65 cm). No statistically significant differences were noted in ejection fraction, percentage of internal diameter shortening (% delta D) and PEP/LVET. The carotid tracing had a bisferiens pulse in five marathon runners. The apexcardiogram showed a bifid systolic thrust in three and absence of abnormal A wave. These abnormalities were related to the overload type of heart as proven by echocardiogram. "Early repolarization syndrome" (abnormal RS-T segment elevation) and notched T waves in ECG had a counterpart a semilunar configuration in the VCG. Three athletes met ECG criteria and one met VCG criteria of LVH. The treadmill exercise ECG was negative in all 12 athletes. Biventricular enlargement and increased left ventricular mass are present in the marathon runner's heart. Myocardial contractility at rest was, however, not statistically different from nonathletes.

Echocardiographic assessment of left ventricular function during the injection of adriamycin

Echocardiography was used to evaluate left ventricular function in 8 children treated with adriamycin for malignant disease. Preejection period (PEP), left ventricular ejection time (LVET) and percent change in left ventricular internal dimension with systole (delta LVID) were measured before, during and immediately after 22 injections of adriamycin as well as 14 injections of other cytotoxic drugs and physiologic saline. No immediate effects on left ventricular function could be discerned. When functional parameters were evaluated longitudinally in patients with relatively higher cumulative doses of adriamycin, percent change in left ventricular internal dimension with systole showed some tendency to decrease, while the other parameters remained essentially unchanged.

A critical review of the systolic time intervals

The theoretical basis for the use of the systolic time intervals has been largely established. The method has been validated by direct measures from within the circulatory system. Standards for equipment and technique have been defined. Numerous clinical studies have demonstrated the value of this quantitative noninvasive technique for assessing left ventricular performance. At present there is need for further studies of the clinical usefulness of the systolic time intervals to improve both diagnosis and therapy of various cardiovascular disorders.

Left ventricular performance in mitral regurgitation assessed with systolic time intervals and echocardiography

Among 22 patients with isolated mitral regurgitation of various origins, systolic time intervals (preejection period [PEP] index, left ventricular ejection time [LVET] index and PEP/LVET) and echocardiographic measures of left ventricular performance (end-diastolic diameter [Dd], end-systolic diameter [Ds], and the percent change in minor axis diameter [% delta D]) were calculated. The patients were classified into two groups, those with a normal or supernormal % delta D (group I, 15 patients) and those with a decreased % delta D (group II, 7 patients). On group analysis, prolongation of the preejection period, shortening of the left ventricular ejection time and an increase in PEP/LVET was generally characteristic of patients with mitral regurgitation. These changes were accentuated when mitral regurgitation was complicated by echocardiographic evidence of diminished left ventricular contractile performance (% delta D less than 30 percent). An increase in PEP/LVET to greater than 0.05 was consistently associated with abnormal left ventricular performance, whereas a normal PEP/LVET ratio reflected normal or supernormal left ventricular performance. An inverse linear relation was found between PEP/LVET and % delta D. When compared with previous data on the relation of these variables among patients without valve insufficiency, PEP/LVET proved to be increased for any level of % delta D in mitral regurgitation. The state of digitalization did not appear to influence the relation between PEP/LVET and % delta D. The use of echocardiographic measurements augments the determination of systolic time intervals in the analysis of left ventricular performance in patients with mitral regurgitation.