Clinical study of late potentials--comparison of late potentials in myocardial infarction, cardiomyopathy and idiopathic ventricular tachycardia

Late potentials (LPs) were studied using the signal averaging technique in 80 patients with myocardial infarction (MI), idiopathic cardiomyopathy (CM) and idiopathic ventricular tachycardia (IVT). In MI, LP duration was 28.4 +/- 12.6 ms in the sustained VT group (I; 8 cases); 18.6 +/- 9.0 ms in the non-sustained VT group (II; 11 cases); and 14.4 +/- 8.6 ms in the non-VT group (III; 21 cases); (p less than 0.05 in I vs II, p less than 0.01 in I vs III and not significant in II vs III). In CM, it was 33.7 +/- 13.0 ms in group I (6 cases); 20.1 +/- 5.9 ms in group II (12 cases); and 7.1 +/- 9.2 ms in group III (14 cases); (p less than 0.01 in I vs II, I vs III and II vs III). The LP duration in IVT (8 cases) was 15.6 +/- 10.4 ms, which was significantly shorter than that of group I in MI and CM (p less than 0.05 vs MI and p less than 0.01 vs CM). Late potential duration was also compared between a pacing-inducible VT group and a non-inducible VT group. The mean value of LP duration in the inducible VT group of MI was significantly longer than that in the non-inducible group (27.8 +/- 3.9 ms in 4 cases vs 17.3 +/- 2.5 ms in 4 cases, p less than 0.05). However, there was no significant difference in LP duration between the inducible and non-inducible groups of CM (22.0 +/- 11.0 ms in 5 cases vs 22.2 +/- 13.6 ms in 5 cases).(ABSTRACT TRUNCATED AT 250 WORDS)     

Rate and extent of recovery of left ventricular function in patients following acute myocardial infarction

To determine the rate and extent of recovery of left ventricular (LV) performance following acute myocardial infarction (MI), peak aortic blood acceleration was measured serially in 26 patients and in 11 normal volunteers with a continuous wave Doppler placed suprasternally. In patients, Doppler measurements were made 20 +/- 2 hours after the acute onset of chest discomfort and were repeated daily for 6 consecutive days. Infarction patients were divided into two groups. Group I consisted of 15 patients who did not have a previous MI and whose present course was not complicated by congestive heart failure (CHF). Group II consisted of 11 patients who had either a previous MI or developed CHF during the present admission. Peak acceleration in the normal volunteers showed minimal daily variations over a period of 6 days. Peak acceleration in the entire group of 26 MI patients increased from 13 +/- 3 m/sec/sec on the day of admission (day 1) to 18 +/- 6 m/sec/sec on day 6 (p less than 0.001). In group I, peak acceleration increased from 13 +/- 4 to 20 +/- 6 m/sec/sec between day 1 and day 6 (p less than 0.001). In group II, however, peak acceleration was 12 +/- 2 m/sec/sec on day 1 and increased to only 15 +/- 4 m/sec/sec on day 6 (NS). These results indicate that LV performance, based upon peak acceleration of blood in the ascending aorta, improves markedly within 6 days in patients suffering their first MI uncomplicated by CHF.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of percutaneous transluminal coronary recanalization (PTCR) on late potentials detected by signal-averaged electrocardiogram in patients with previous myocardial infarction

The purpose of this study was to assess the effect of percutaneous transluminal coronary recanalization (PTCR) on late potentials (LP) in patients with previous myocardial infarction (MI). The signal-averaged ECG was recorded by Fukuda VCM-3000 in 54 patients with anterior MI (average of 32 months after onset of MI). Fifty four patients were divided into two groups: Group A was comprised of 29 patients who underwent PTCR, and Group B was comprised of 25 patients who didn't receive PTCR. Ventricular arrhythmias detected by 24 hour Holter monitoring, and left ventriculographic findings were also evaluated. The presence of LP was defined as low amplitude signals (less than 15 microV) in the last 40 msec of the filtered QRS complex. The incidence of LP was significantly higher in Group B than in Group A (32% vs 7%, p less than 0.01). The presence of PVCs and ejection fraction (EF), LV end-diastolic volume (EDV), LV end-systolic volume (ESV) and % abnormally contracting segment (% ACS) were not significantly different in each respective groups. However, ESV and % ACS were significantly larger (p less than 0.05), and EF was significantly smaller (p less than 0.01) in patients with LP (+) than in patients with LP (-). LP was present in two patients who had undergone PTCR (TIMI grade 2) unsuccessfully, whereas it was not present in the 27 patients with successful PTCR (TIMI grade 3). It was concluded that successful recanalization of the infarct-related arteries may reduce the incidence of LP.     

Square root sign of left ventricular diastolic pressure curve in atrial septal defect

The square root (dip and plateau) sign was observed in 7 of 21 adult patients with atrial septal defect (ASD). This study evaluated left ventricular (LV) diastolic filling dynamics and hemodynamic findings in 7 patients (Group 1) with, and 14 patients (Group 2) without the square root sign; 10 normal subjects (Group 3) served as controls. No significant differences were observed in LV end-diastolic and end-systolic volumes, ejection fraction, or left to right shunt. In Group 1, 77% of LV filling was completed in the first half of diastole; this percentage was 49% and 53% in Groups 2 and 3, respectively (both p less than 0.01 versus Group 1). Early diastolic filling velocity (at 20% of diastole) in Group 1 was significantly greater, and late diastolic filling velocity (at 80% and 90% of diastole) was reduced in Group 1 compared to those in Groups 2 and 3 (all p less than 0.05). The average values for right and left ventricular end-diastolic pressures were significantly higher in Group 1 (11 +/- 2 and 10 +/- 4 mmHg, p less than 0.05) than Group 2 (7 +/- 2 and 7 +/- 2 mmHg, p less than 0.05). It is suggested that a constrictive pathophysiology due to 4 chambers interaction or right ventricular constraint may play a role in the genesis of the square root sign in ASD.     

Comparison of left ventricular function and infarct size in patients with and without persistently positive technetium-99m pyrophosphate myocardial scintigrams after myocardial infarction: analysis of 357 patients

One hundred nine patients with persistently positive technetium-99m pyrophosphate (Tc-99m-PPi) myocardial scintigrams 6 months after acute myocardial infarction (MI) (Group A) and 185 patients without such persistently positive scintigrams (Group B) were compared with regard to enzymatically determined infarct size, early and late measurements of left ventricular (LV) function determined by radionuclide ventriculography, and preceding clinical course during the 6 months after MI. The CK-MB-determined infarct size index in Group A (17.4 +/- 10.6 g-Eq/m2) did not differ significantly from that in Group B (16.0 +/- 14.6 g-Eq/m2). Similarly, myocardial infarct areas in the 2 groups, determined by planimetry of acute Tc-99m-PPi scintigrams in those patients with well-localized 3+ or 4+ anterior pyrophosphate uptake, were not significantly different (35.7 +/- 13.4 vs 34.4 +/- 13.1 cm2, respectively). However, patients in Group A had significantly lower LV ejection fractions than those in Group B, both within 18 hours of the onset of MI (0.42 +/- 0.14 vs 0.49 +/- 0.14, p less than 0.01) and at 3 months after MI, both at rest (0.42 +/- 0.14 vs 0.51 +/- 0.14, p less than 0.01) and at maximal symptom-limited supine bicycle exercise (0.44 +/- 0.17 vs 0.51 +/- 0.17, p less than 0.01). Peak exercise levels achieved in the 2 groups were not significantly different. Furthermore, patients in Group A demonstrated a greater incidence of congestive heart failure during the initial hospital admission (41 vs 24%; p less than 0.01) and a greater requirement for digoxin (p less than 0.05) and furosemide (p less than 0.01) after discharge.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nonuniform recovery of excitability in the left ventricle

The purpose of this study was to determine left ventricular activation, dispersion of refractoriness, and total recovery time in patients with coronary artery disease and ventricular tachycardia and in patients with the long QT syndrome and to compare these patients with a group of normal patients. Left ventricular endocardial catheter mapping and left ventricular refractory period determination were performed in 18 patients. Group 1 consisted of seven patients with no heart disease and no arrhythmia; group 2 consisted of six patients with previous infarction and sustained ventricular tachycardia; and group 3 consisted of five patients with prolonged QT interval and previous cardiac arrest. Total left ventricular endocardial activation was significantly longer in group 2 (75 +/- 23 msec, mean +/- SD) compared with group 1 (34 +/- 9 msec, p less than 0.01) and group 3 (42 +/- 5 msec, p less than 0.05). Dispersion of refractoriness was significantly greater in group 3 (87 +/- 27 msec) than in group 1 (40 +/- 14 msec, p less than 0.01) and group 2 (53 +/- 14 msec, p less than 0.05). Dispersion of total recovery time was significantly greater in group 2 (90 +/- 30 msec) than in group 1 (52 +/- 14 msec, p less than 0.05) as well as group 3 (114 +/- 43 msec) compared with group 1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pattern of left ventricular diastolic filling associated with right ventricular enlargement

Right ventricular (RV) dilatation associated with pressure overload may alter left ventricular (LV) geometry resulting in abnormal diastolic function as demonstrated by a smaller LV diastolic volume for a given LV diastolic pressure. To determine whether abnormalities in LV geometry due to RV dilatation result in abnormalities in the LV diastolic filling pattern, we obtained pulsed Doppler transmitral recordings from 23 patients with RV dilatation with RV systolic pressure estimated to be less than 40 mm Hg (group 1), 18 patients with RV dilatation and RV systolic pressures greater than or equal to 40 mm Hg (group 2) and 33 normal patients. RV systolic pressures were estimated from continuous wave Doppler peak tricuspid regurgitation velocities using the modified Bernoulli equation. Diastolic filling parameters in group 1 patients were similar to normals. In group 2 patient, increased peak atrial filling velocity (76 +/- 14 vs 57 +/- 12 cm/s, p less than 0.001), decreased peak rapid filling velocity/peak atrial filling velocity (1.1 +/- 0.4 vs 1.5 +/- 0.4, p less than 0.01), increased atrial filling fraction (41 +/- 14 vs 30 +/- 10%, p less than 0.01) and prolongation of the atrial filling period (171 +/- 47 vs 152 +/- 39 ms, p less than 0.05) were noted compared with the normal group. RV end-diastolic size and LV end-systolic shape were significantly correlated with the atrial filling fraction in group 2 patients. In patients with RV dilatation and RV systolic pressures greater than or equal to 40 mm Hg, there is increased reliance on atrial systolic contribution to the LV filling volume.     

Impaired left ventricular filling and regional diastolic asynchrony at rest in coronary artery disease and relation to exercise-induced myocardial ischemia

Impaired left ventricular (LV) diastolic filling at rest is frequently observed in patients with coronary artery disease (CAD) who have normal LV systolic function and no previous infarction. To test the hypothesis that abnormal diastolic function at rest might reflect the functional severity of CAD, as estimated by exercise-induced ischemia, the relation between regional and global LV diastolic function at rest and during exercise-induced ischemia was evaluated in 49 patients with radionuclide angiography. All patients had normal systolic function at rest. Group 1 (n = 26) patients manifested a normal ejection fraction response to exercise and group 2 (n = 23) patients an abnormal response. Data obtained from 22 age-comparable normal volunteers were used for comparison. Although regional and global diastolic function were not different between normal subjects and group 1 patients, peak filling rate was lower in group 2 patients than in normal subjects (2.5 +/- 0.8 vs 3.2 +/- 0.6 end-diastolic counts/s; p less than 0.01). Moreover, regional diastolic asynchrony, as assessed from the radionuclide data by using a regional sector analysis of the LV region of interest, was greater in group 2 patients (46 +/- 44 ms) than in both normal subjects (25 +/- 16 ms; p less than 0.05) and group 1 patients (23 +/- 16 ms; p less than 0.05). Thus, among patients with CAD and with normal LV systolic function at rest, impaired LV filling and regional asynchrony predict a greater degree of exercise-induced ischemia, suggesting a greater extent of jeopardized myocardium.     

A comparative study of two different methods for detecting late potentials in patients with and without ventricular tachycardia

To compare the clinical utility of 2 methods in detecting late potentials (LPs), our method (K-method) and Simson's method (S-method) were used in 96 patients with or without ventricular tachycardia(VT). Indices of LPs were LP duration (LPd) in K-method, and mean voltage of the filtered vector magnitude for the last 40 ms of the QRS complex (V40) in S-method. For patients with underlying cardiac disease (UD), LPd in patients with sustained VT (s-VT; 39.4 +/- 20.1 ms) was significantly longer than that in patients with nonsustained VT (ns-VT; 16.1 +/- 6.6 ms) or without VT (non-VT; 13.3 +/- 5.2 ms) (p less than 0.01), while V40 in patients with s-VT, ns-VT, and non-VT were 24.7 +/- 26.4 microV, 56.5 +/- 31.7 microV, and 98.1 +/- 75.3 microV, respectively (p less than 0.05). Patients without UD had less apparent LPs in both methods. There was a significant reciprocal correlation between LPd and V40; LPd = (378/V40) + 6.66 (r = 0.89, p less than 0.001). The sensitivity and specificity with the highest predictive accuracy for s-VT in K-method were 50% and 100% and those in S-method were 50% and 97% respectively. In conclusion, despite many differences in these 2 methods, sensitivity and specificity were nearly equal and they were both useful to identify patients with s-VT.     

The effect of successful angioplasty on variables of signal-averaged electrocardiogram and ventricular wall motion in patients with a first myocardial infarction

The correlation among three variables of late potentials (LPs) obtained by signal-averaged electrocardiography (SAECG) and improvement of ventricular wall motion estimated by echocardiography were studied in 66 patients with a first acute myocardial infarction (MI). Patients with bundle-branch block, intraventricular conduction delay, multi-vessel disease, previous MI, repeat percutaneous transluminal coronary angioplasty (PTCA), or evidence of reinfarction during a 6-month follow-up were excluded. A total of 66 patients was divided into two groups, with (Group 1: n = 27, age 56 ± 11) or without (Group 2: n = 39, age 61 ± 10) improvement of ventricular wall motion. Three variables of LPs and ventricular wall motion index (WMI) estimated and scored by echocardiography at admission (WMI 1) and at 6 months after MI (WMI 2) were compared in each group. In Group 1 (WMI 1 vs. WMI 2, p < 0.002), 20 of 27 patients underwent successful angioplasty; in Group 2 (WMI 1 vs. WMI 2, p = NS), 7 of 39 patients had successful emergency angioplasty. There were significant differences in three variables of LPs between the time of admission and at 6 months after MI in Group 1 but not in Group 2. Higher incidence of LPs and greater frequency of successful emergency PTCA were found in Group 1 compared with Group 2. These results suggest that because myocardial ischemia is reversed by successful angioplasty, ventricular wall motion is improved and the arrythmogenic substrate that generates LPs is stabilized electrically. Stunned or hibernating myocardium may be the arrhythmogenic substrate that generates LPs.     

Prognostic value of two-dimensional echocardiography before aneurysmectomy in anterior aneurysm of the left ventricle

The prognostic value of echocardiographic apical 4 chamber recordings was assessed retrospectively in 18 patients who underwent left ventricular aneurysmectomy following anterior wall myocardial infarction. After an average follow-up period of 2 years, 7 patients had died or remained in functional Classes III or IV (Group 1) and 11 patients had satisfactory clinical outcomes (Group 2). There were no significant clinical or coronary angiographic differences between the two groups. The left ventricular surface area, transverse diameter and fractional shortening of the surface were also comparable in the two groups. The surface area of the aneurysm was greater in patients in Group 1 (37.4 +/- 11.8 cm2 vs 21.1 +/- 15.8 cm2, p less than 0.05). However, the more discriminating parameters were those related to the non-aneurysmal contractile zones (NACZ). Patients in Group 1 had a smaller relative surface area of the NACZ than those in group 2; 6 of the 7 patients in Group 1 had NACZ of less than 40 per cent of the left ventricle compared with none of the patients in Group 2 (p less than 0.001). In addition, the function of the NACZ was significantly worse in Group 1: surface fractional shortening: 9.6 +/- 10.2% vs 32.6 +/- 8.3% (p less than 0.001); ejection fraction: 20.7 +/- 9.1% vs 41.6 +/- 6.1% (p less than 0.001). All patients in Group 1 and none in Group 2 had ejection fractions of the NACZ of less than 30 per cent. Therefore, the apical 4 chamber view provides valuable prognostic information in patients who are candidates for surgical resection of left ventricular anterior wall aneurysms.     

Alterations in myocyte shape and basement membrane attachment with tachycardia-induced heart failure

Chronic supraventricular tachycardia (SVT) results in left ventricular (LV) dilatation and dysfunction. However, the underlying mechanisms responsible for LV failure in this setting are not known. LV force production is dependent on the coupling of myocytes to the extracellular matrix, which is mediated through the basement membrane. This study was designed to determine whether alterations in myocyte geometry and basement membrane attachment are associated with LV failure in a pacing-induced model of cardiomyopathy. Echocardiographic measurement of LV function was performed in six pigs after 3 weeks of pacing-induced SVT (240 beats/min) and in eight sham-operated controls. Myocytes from these hearts were isolated, and attachment studies to specific components of the basement membrane were performed using laminin, fibronectin, and collagen IV. The SVT group when compared with the control group showed a significant reduction of LV fractional shortening (14 +/- 2% versus 31 +/- 2%, respectively; p less than 0.05), increased end-diastolic dimension (50 +/- 1 versus 35 +/- 1 mm, respectively; p less than 0.05), and lengthening of isolated myocytes (196 +/- 18 versus 142 +/- 9 microns, respectively; p less than 0.05). Myocyte attachment to laminin (50 micrograms/ml) was significantly decreased at 60 minutes in the SVT group compared with the control group (18.2 +/- 4.5 versus 60.9 +/- 4.5 cells/mm2, respectively; p less than 0.05). Similar reductions in myocyte attachment to fibronectin and collagen IV were observed. Ultrastructural examination of LV sections revealed focal disruptions of the basement membrane-sarcolemmal interface and a reduced number of sarcolemmal festoons in SVT hearts compared with control hearts (0.8 +/- 0.6 versus 2.8 +/- 0.8/4 microns, respectively; p less than 0.05). These alterations in myocyte morphology and basement membrane attachment may contribute to the LV failure associated with chronic SVT. Further, these structural changes may play a significant role in the progression of ventricular dysfunction as well as recovery from chronic SVT.     

Cardiovascular factors influencing survival in end-stage renal disease treated by continuous ambulatory peritoneal dialysis.

To determine whether hemodynamic advantages of continuous ambulatory peritoneal dialysis (CAPD) over intermittent hemodialysis are associated with improved survival and identify cardiac risk factors for early death, 55 patients on CAPD (age 58 +/- 11 years; CAPD duration: 29 +/- 25 months) were followed in a noninvasive prospective analysis over 35 months. At follow-up, 25 patients had died; 16 deaths were related to cardiovascular causes. Nonsurvivors were older (62 +/- 8 vs 55 +/- 12 years; p less than 0.015) and had more angina pectoris (40 vs 20%; p less than 0.05) than survivors, but had comparable CAPD duration, arterial blood pressure, hemoglobin, serum creatinine, urea and parathyroid hormone concentrations. On echocardiography, nonsurvivors had a lower mean left ventricular (LV) ejection fraction (59 +/- 15 vs 66 +/- 9%; p less than 0.03), higher LV end-systolic volume indexes (49 +/- 31 vs 36 +/- 13 ml/m2; p less than 0.03) and a shorter mean LV ejection time (371 +/- 41 vs 390 +/- 22 ms; p less than 0.03). LV muscle mass, LV diastolic and left atrial dimensions, stroke volume and cardiac index were comparable. On pulsed Doppler analysis of a subgroup of 48 patients in sinus rhythm and without valve disease, nonsurvivors (n = 23) had more severely decreased ratios of peak early/atrial filling velocities (0.66 +/- 0.18 vs 0.81 +/- 0.24; p less than 0.03) and increased atrial filling fractions (52 +/- 11 vs 46 +/- 9%; p less than 0.03) than survivors. Mean isovolumic relaxation periods were increased in both groups (135 +/- 39 vs 129 +/- 33 ms; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Differing responses in right and left ventricular filling, loading and volumes during positive end-expiratory pressure

Using a combined hemodynamic and radionuclide technique, 20 patients with varied ventricular function were evaluated during positive end-expiratory pressure (PEEP) application. Left ventricular (LV) and right ventricular (RV) ejection fractions and cardiac output were measured, and ventricular volumes were derived. Seven patients (group 1) who had an increase in LV end-diastolic volume with PEEP and 13 patients (group 2) who had the more typical response, a decrease in LV end-diastolic volume with PEEP, were identified. Compared with group 2, group 1 patients had a higher incidence of coronary artery disease (5 of 7 vs 1 of 13, p less than 0.005) and lower cardiac output (3.9 +/- 1.6 vs 9.1 +/- 3.2 liters/min, p less than 0.005), LV ejection fraction (27 +/- 13 vs 51 +/- 21%, p less than 0.05), RV ejection fraction (15 +/- 6 vs 32 +/- 8%, p less than 0.005) and peak filling rate (1.32 +/- 0.43 vs 3.51 +/- 1.70 end-diastolic volumes/s, p less than 0.05). LV and RV volumes increased and peak filling rate decreased with PEEP in group 1, whereas in group 2 LV volume decreased and RV volume and peak filling rate remained unchanged. Using stepwise regression analysis, the change in LV volume with PEEP was related directly to baseline systemic vascular resistance and inversely to baseline blood pressure. Similarly, the change in peak filling rate with PEEP was inversely related to the change in RV end-diastolic volume. Thus, the hemodynamic response to PEEP is heterogeneous and may be related to LV ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Emergent angioplasty prevents left ventricular dilation in patients with acute anterior wall myocardial infarction and cardiogenic shock

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) reduces in-hospital mortality and improves long-term outcome in patients with acute myocardial infarction (MI) complicated by cardiogenic shock. However, no study has evaluated the effects of different reperfusion therapies on left ventricular (LV) dimension and cardiac function in long-term survivors of MI with cardiogenic shock. HYPOTHESIS: We investigated the effects of PTCA on the development of LV dilation in patients who survived MI complicated by cardiogenic shock. METHODS: We studied 34 patients with a first MI and cardiogenic shock in whom two-dimensional echocardiography was performed immediately after admission and 1 month after infarction. Group A consisted of 17 patients who underwent emergent PTCA during the acute phase of MI, and Group B consisted of 17 patients who did not undergo PTCA. We also studied 119 patients with a first uncomplicated acute anterior MI, including 53 who underwent PTCA (Group C) and 66 who did not (Group D). The length and wall thickness of the infarcted and noninfarcted endocardial segments were determined immediately after MI and 1 month later, and LV ejection fraction (LVEF) was measured during the chronic phase. RESULTS: The lengths of the infarcted and noninfarcted endocardial segments were significantly greater in Group B than in the other three groups (p < 0.05). The LVEF was significantly lower in Group B than in the other three groups (p < 0.05). CONCLUSIONS: We conclude that PTCA performed in patients during the acute phase of MI complicated by cardiogenic shock lowers in-hospital mortality and prevents both LV dilation and a decrease in LVEF.     

Role of infarct expansion in rupture of the ventricular septum after acute myocardial infarction: a two-dimensional echocardiographic study

To verify the role of infarct expansion (IE) in ventricular septal rupture (VSR) after transmural acute myocardial infarction (TAMI), topographic parameters were measured using tomographic imaging with two-dimensional echocardiography (2-D echo) and computer-aided analysis in four groups of patients: 8 patients with VSR (Group 1); 24 patients with TAMI but no mechanical complications (Group 2); 11 normal athletes (Group 3); 5 adults with congenital ventricular septal defect (Group 4). Measurements made on end-diastolic outlines of mid-left ventricular (LV) short-axis images included: LV asynergy (akinesis and/or dyskinesis), expansion index (asynergy/nonasynergy-containing endocardial segment length), thinning ratio (asynergic/nonasynergic wall thickness), and new indexes of regional shape distortion (RSD) by quantifying the deviation of the actual asynergic segment from the ideal asynergic arc constructed using the nearly circular nonasynergic contour. In Group 1, clinical IE (hypotension, congestive heart failure, no signs of new infarction) preceded detection of the VSR and portable 2-D echo showed the VSR associated with LV asynergy, marked IE, and RSD. Although Groups 1 and 2 had similar LV asynergy (28.7 vs. 26.9% LV) and ejection fraction (38.9 vs. 41.8%), Group 1 had higher expansion index (1.50 vs. 1.17, p less than 0.05), lower thinning ratio (0.54 vs. 0.67, p less than 0.005), and higher RSD parameters (e.g., peak distortion, Pk or maximum radial distance from the ideal arc, 19.3 vs. 3.9 mm, p less than 0.01; area of distortion, Ad, 7.4 vs. 1.1 cm2, p less than 0.05) than Group 2. Groups 3 and 4 had normal regional and global function and no evidence of expansion, thinning, or RSD. Thus, IE with marked diastolic RSD on an early 2-D echo after TAMI might identify patients at risk for VSR.     

Involvement and function of the right ventricle in acute myocardial infarct. Hemodynamic, echocardiographic and angioscintigraphic correlations

To assess the acute effects of myocardial infarction on right ventricular function 22 patients were studied utilizing right heart catheterization, radionuclide angiography and two dimensional echocardiography. Thirteen patients had inferior myocardial infarction (Group I) and 9 anteroseptal or anterior (Group II). Hemodynamic findings suggesting right ventricular infarction were present in 3 patients of Group I. Mean radionuclide right ventricular ejection fraction was lower in inferior myocardial patients (38.2 +/- 7.6-Group I vs 50.3 +/- 11.4-Group II, p less than 0.005), while left ventricular ejection fraction in anteroseptal, and anterior myocardial infarction patients (36.8 +/- 10.5-Group II vs 55.9 +/- 7.6-Group I, p less than 0.001). Six patients in Group I presented a depressed radionuclide right ventricular ejection fraction (less than 40%): moreover right ventricular ejection fraction correlated with left ventricular ejection fraction in Group II (r = 0.79, p less than 0.001) but not in Group I (r = 0.55, p = NS). By mean of 2 dimensional echocardiography Group I patients had an increased right ventricular end diastolic area (15.3 +/- 3.8 vs 12.1 +/- 1.2 cm2, p less than 0.05) while Group II an increased right ventricular free wall motion (47.3 +/- 10.7 vs 32.4 +/- 14.1%, p less than 0.005); right ventricular end diastolic area correlated with right ventricular ejection fraction only in Group I (r = 0.60, p less than 0.05). Five patients in Group I and no patients in Group II had an enlarged right ventricular end diastolic area. Therefore, radionuclide and echocardiographic evidence of right ventricular involvement were not always associated with abnormal hemodynamics. Thus, the damaged right ventricular chamber dilates to allow an adequate stroke volume in presence of low ejection fraction; hemodynamic significant right ventricular myocardial infarction becomes evident only in patients with more severe right ventricular compromise; the increase in right ventricular free wall motion in anterior myocardial infarction patients compensates the loss of contribution of interventricular septum contraction.     

Left ventricular ejection fraction response during exercise in asymptomatic systemic hypertension

To study the effect of mild-to-moderate elevations in diastolic blood pressure (BP) on systolic left ventricular (LV) function, 28 hypertensive patients and 20 normal subjects underwent upright exercise first-pass radionuclide angiography. All were asymptomatic, had normal rest and exercise electrocardiographic findings and no evidence of LV hypertrophy or coronary artery disease. LV function at rest was similar in the 2 groups, but with exercise hypertensive patients had a greater end-systolic volume (69 +/- 19 vs 51 +/- 19 ml, p less than 0.002) and lower ejection fraction (EF) (0.59 +/- 0.09 vs 0.72 +/- 0.07, p less than 0.0001), stroke volume (101 +/- 28 vs 130 +/- 36 ml, p less than 0.005) and peak oxygen uptake (23 +/- 7 vs 33 +/- 9 ml/kl/min, p less than 0.05). Hypertensive patients were separated into 3 groups: group 1-12 patients with an increase in EF with exercise greater than or equal to 0.05; group 2-7 patients with a change in EF with exercise less than 0.05; and group 3-9 patients with a decrease in EF with exercise greater than or equal to 0.05. Group 3 hypertensive patients were older, had a higher heart rate at rest and lower peak oxygen uptake. Rest LV function was similar in the 3 hypertensive subgroups, but exercise end-systolic volumes were higher in groups 2 and 3. Exercise thallium-201 images was normal in all but 1 of 14 hypertensive group 2 or 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Validity of the ECG diagnosis of left ventricular hypertrophy in normotensive and moderately hypertensive men when using the echocardiographic assessment of left ventricular mass index as reference.

The diagnostic validity of ECG criteria for left ventricular hypertrophy (LVH) was assessed in 100 men aged 22-64 (mean 47) years with moderate hypertension (Group 1) and 95 age-matched normotensive men (Group 2) using echocardiographic recordings of LV mass index (MI) as reference. A diagnosis of LVH was made in subjects with LVMI greater than or equal to 125 g/m2. Mean LVMI was 126 +/- 34 g/m2 in Group 1 vs. 100 +/- g/m2 in Group 2 (P less than 0.001), and the prevalence of LVH was 48% and 11% respectively (P less than 0.001). The mean ECG voltage according to Sokolow-Lyon (S-L) was 28 +/- 8 mm in Group 1 and 27 +/- 7 mm in Group 2 (NS); with 19% having LVH in Group 1 and 14% in Group 2 (NS). Using the Cornell criterion Group 1 had on average 15 +/- 6 mm vs. 12 +/- 5 mm in Group 2 (P less than 0.001), but only two Group 1 patients had LVH. In Group 2 a significant negative correlation between age and S-L voltage was found (r = 0.33, P less than 0.001). LVMI was not correlated with any of the two voltage criteria using linear regression analysis whereas multiple regression analysis revealed a weak, but significant correlation between LVMI and S-L voltage in Group 1 (t = 2.06, P = 0.04). No subject had LV strain pattern or LVH according to the Romhilt Estes point score system. In the assessment of possible LVH in normal or moderately hypertensive men less than 65-70 years of age, ECG has limited value.     

Influence of left ventricular asynchrony on filling in coronary artery disease

To evaluate whether the extent of left ventricular (LV) asynchrony plays a role in the impairment of LV rapid filling in patients with coronary artery disease (CAD), 48 patients underwent both radionuclide angiography and cardiac catheterization. Patients were divided into group I (n = 33), with normal LV kinesis or only mild hypokinesia, and group II (n = 15), with LV dyskinesia or akinesia. Radionuclide ejection fraction was higher in group I than in group II (62 +/- 12 vs 44 +/- 20%; p less than 0.001). Peak filling rate was significantly lower in group II (1.9 +/- 0.8 vs 2.6 +/- 0.9 end-diastolic counts/s; p less than 0.01). Time to end-systole coefficient of variation, an index of the extent of LV asynchrony, was significantly higher in group II than in group I (43 +/- 10 vs 35 +/- 6; p less than 0.0002). In group I, a highly significant inverse relation was found between this index of asynchrony and peak filling rate (r = 0.71; p less than 0.0001). This correlation was found even when time to end-systole coefficient of variation was normalized to the RR interval (r = 0.49; p less than 0.01) and when peak filling rate was expressed in stroke counts (r = 0.57; p less than 0.001). The correlation between peak filling rate and index of asynchrony was maintained up to an end-systole coefficient of variation value of approximately 35. In group II patients (most with an asynchrony value greater than or equal to 35) no relation was found between time to end-systole coefficient of variation and peak filling rate.