Echoventriculography in acute myocardial infarction. IV. Infarct size and reliability by pathologic anatomic correlations

Usefulness of multiaxis echocardiography in assessment of the left ventricle in ischemic heart disease. A review

Echoventriculography, a multiaxis M-mode echocardiographic technique, was developed to examine in detail the regional wall motions of the left ventricle. The basic technical aspects and limitations are described, and experience is reviewed on 263 healthy subjects or patients with ischaemic heart disease. The reliability in detecting site and size of asynergic segments was excellent as related to electrocardiographic and thallium scintigraphic sites of acute infarction, and with left ventricular cineangiograms in chronic coronary heart disease. The correlation with pathologic anatomic size of infarct in 24 consecutive patients was r = 0.88 (p less than 0.001) when expressed by a percentage of the left ventricular horizontal circumference. 94% of 111 infarcted segments were correctly detected by echo; only the posteroseptal and the most lateral regions remain out of the methodological range. The method separated old infarct scars from fresh necrosis. Decreasing echo contraction index correlated with increasing severity of coronary obstructions in 43 patients studied for coronary artery surgery. In 15 infarct patients the M-mode technique was more sensitive than two-dimensional echocardiography in recording asynergic segments or endocardial echoes. The multiple segmental echoventriculographic index decreased parallel with clinical severity of acute infarction (r = -0.79, p less than 0.001; 30 patients). There was a 88% (p less than 0.01) concordance between the reduction of the ST segments (-30%) and the recovery of the mechanical function in the ischaemic myocardial segments (+26%) after beta blockade with pindolol in 22 patients with acute infarction. Methylprednisolone showed no improvement. With dopamine the left ventricular size decreased markedly (p less than 0.0005). Echoventriculography thus seems to be very informative in evaluation of chronic or acute left ventricular dysfunction, despite the rather demanding nature of the technique in practice.

Quantification of left ventricular wall dysfunction by M-mode echocardiographic mapping in heart failure following acute myocardial infarction

Echocardiographic mapping was performed in 44 patients on arrival in hospital and day 2 following acute myocardial infarction (AMI). To evaluate left ventricular (LV) function the per cent deviation of the mean systolic wall velocity (PD-V) from the normal was measured from 16 LV segments. Adequate data were obtained from 89% of the segments. The number of hypokinetic segments was somewhat higher in anterior than inferior AMI, reaching significance (p less than 0.05) on day 2. Dyskinetic segments were also more common in patients with anterior infarction (p less than 0.001), who also had significantly higher enzyme maxima than patients with inferior AMI (p less than 0.01). Enzyme maxima correlated well with the sum of PD-V from all hypokinetic segments on day 1 (r = 0.79, p less than 0.01). Compensatory hyperkinesia was more common in inferior than anterior AMI (p less than 0.001). Global LV function, estimated by subtracting the number of hyper- from hypokinetic segments (score sigma S:Adj), was significantly related to heart failure (Killip classification) (p less than 0.01) and the respiratory rate (r = 0.71, p less than 0.01) in the acute phase as well as to heart failure during the first post AMI month (New York Heart Association classification).

Contrast echocardiography in acute myocardial ischemia. III. An in vivo comparison of the extent of abnormal wall motion with the area at risk for necrosis

To define the in vivo relation between abnormal wall motion and the area at risk for necrosis after acute coronary occlusion, 11 open chest dogs were studied. Five dogs underwent left anterior descending coronary artery occlusion and six underwent left circumflex artery occlusion. Area at risk was defined at five short-axis levels (mitral valve, chordal, high and low papillary muscle and apex) using myocardial contrast echocardiography. Wall motion was measured in the cycles preceding injection of contrast medium. Two observers used two different methods to measure wall motion. In method A, end-diastolic to end-systolic fractional radial change for each of 32 endocardial targets was determined. The extent of abnormal wall motion was then calculated using three definitions of wall motion abnormality: akinesia/dyskinesia, fractional inward endocardial excursion of less than 10%, and fractional inward endocardial excursion of less than 20%. In method B, the information from the entire systolic contraction sequence was analyzed and correlated with a normal contraction pattern. The best linear correlation between area at risk (AR) and abnormal wall motion (AWM) was achieved using method B and expressed by the following linear regression: AWM = 0.92 AR + 3.0 (r = 0.92, p less than 0.0001, SEE = 1.7%). Of the three definitions of abnormality used in method A, the best correlation was achieved between area at risk and less than 10% inward endocardial excursion and was expressed by the following polynomial regression: AWM = -0.01 AR2 + 1.5 AR -0.14 (r = 0.92, p less than 0.001, SEE = 1.7%). These data demonstrate that there is a definite relation between area at risk and abnormal wall motion but that this relation varies depending on the method used to analyze wall motion. However, wall motion during acute ischemia is also influenced by the loading conditions of the heart. Because these may vary in a manner that is independent of the ischemic process, measurement of both risk area and abnormal motion may provide a more comprehensive assessment of cardiac function in myocardial ischemia than is provided by the measurement of either alone.

Echocardiography in acute infectious myocarditis: relation to clinical and electrocardiographic findings

Multidirectional M-mode echocardiography (echo) was used to investigate functional and structural changes of the heart in 68 consecutive patients with acute or subacute infectious myocarditis. Forty patients had mild myocardial involvement evident by gradually changing ST-segment or T-wave alterations (not responsive to beta blockade) in serial ECGs; 21 patients also had loud S3 gallop and palpable paradoxical cardiac pulsations, and 7 patients had severe congestive heart failure. Echo revealed regional changes in the left ventricular (LV) contraction in all patients with acute myocarditis. The site and size of the asynergic wall motion abnormalities correlated with both the clinical severity of the disease and the location of the T-wave inversions in the ECG. In mild myocarditis hypokinesia only was noted in 1 to 3 sites (mean 2.3) of 11 recorded LV sites (21%). In moderate myocarditis, the local asynergic change was mainly akinesia and more widespread, being surrounded by hypokinetic regions (3.8 of 11 sites, 35% of the LV sites). In congestive heart failure, the hypokinetic or akinetic segments affected almost the entire left ventricle (7.6 of 11 sites, 69% of the LV sites) (p less than 0.001 between the groups). In the last group, all patients had strong "fibrotic" echoes, in contrast to mild myocarditis (13%). In mild infectious myocarditis the contraction disturbance of the asynergic regions also generated a peculiar "quivering" pattern with thin echo lines. In the uninvolved segments, hyperkinesia was observed in most patients. The LV end-diastolic diameters in the 3 groups were 51 +/- 5, 58 +/- 4 and 65 +/- 5 mm (p less than 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of verapamil in patients with acute myocardial infarction: hemodynamics and function of normal and ischemic left ventricular myocardium

We evaluated the effects of intravenous verapamil, a calcium antagonist, on hemodynamics and regional left ventricular (LV) performance in patients with acute myocardial infarction (AMI). Twenty patients having uncomplicated infarction or moderate heart failure were randomized to receive either verapamil or placebo and were studied a mean of 12 hours after onset of symptoms. Verapamil, 7.5 mg intravenously, acutely reduced systolic arterial pressure (p less than 0.0005), systemic vascular resistance, and LV stroke work (p less than 0.005) and rate-pressure product (p less than 0.05); the heart rate did not alter. The Frank-Starling relationship by Swan-Ganz catheter did not change for 1 hour. Segmental wall motion amplitudes were recorded from eight standardized segments around the left ventricle by a multidirectional M-mode echocardiographic technique. The systolic wall motion of the uninvolved LV segments and LV cavity size did not change after verapamil. Verapamil improved mechanical performance in the ischemic segments (p less than 0.005). Therefore, the overall regional contractile function of the left ventricle improved as well (by 11% to 13%, p less than 0.05). This echocardiographic improvement continued after the acute vasodilatory response of intravenous verapamil subsided and was preserved for 1 week, the patients having had oral verapamil, 240 mg daily. Chest pain was relieved in five of the six patients having ongoing slight pain before verapamil injection. No sequential hemodynamic or echocardiographic changes occurred in the placebo-treated patients. Thus, in patients with uncomplicated AMI, verapamil improve contractile function of the acutely ischemic LV segments by hemodynamic unloading and/or by direct myocardial effect, without manifest depression of the uninvolved myocardium.

Simultaneous assessment of segmental and global left ventricular function by two-dimensional echocardiography in acute myocardial infarction

Both segmental and global left ventricular performance were assessed simultaneously in 29 patients with acute myocardial infarction using two-dimensional echocardiography. Comparisons were made between left ventricular wall motion versus peak CK-MB, site of infarction, and occurrence of heart failure. Two-dimensional echocardiography identified areas of dyssynergy which corresponded to electrocardiographic areas of infarction in 89% of all cases. Patients with heart failure had more dyssynergic segments, and these segments manifested more severe dyssynergy than patients without heart failure. Patients with severe global dysfunction manifested higher peak CK-MB values, and those with anterior infarction had more global dyssynergy than did those patients with inferior infarction. These observations suggest that two-dimensional echocardiography is a useful technique for localization and assessment of segmental and global dyssynergy in acute myocardial infarction. Information so derived correlates with the clinical status of patients with acute myocardial infarction, and may offer important insights into both prognosis and treatment.

Cardiac safety of acute beta blockade: intrinsic sympathomimetic activity is superior to beta-1 selectivity

Regional myocardial function was assessed by multidirectional echocardiography from eight standardized segments around the left ventricle. Thirty-six subjects (healthy, severe angina pectoris, or acute myocardial infarction) were studied 15 minutes either after the beta 1-selective beta-blocking drug metoprolol had been administered in total doses of 2 and 10 mg intravenously or after pindolol, a beta blocker with intrinsic sympathomimetic activity (ISA), in total doses of 0.2 and 1.0 mg intravenously had been given. Metoprolol and pindolol reduced rate-pressure product (p less than 0.001 each), heart rate (p less than 0.001), and systolic blood pressure (p less than 0.05 to 0.001) in almost the same way. In patients with acute myocardial infarction, 0.2 mg pindolol improved ST segments by 33% and 2 mg metoprolol by 18%. Left ventricular diameter increased (p less than 0.001) and ejection fraction decreased (p less than 0.05) after metoprolol but not after pindolol. Pindolol did not reduce wall motion amplitudes of healthy myocardial segments, while metoprolol did ( p less than 0.01). The overall contractile function of the left ventricle is characterized by composite segmental amplitudes from both ischemic and healthy ventricular regions. In ischemic hearts this function remained unchanged after metoprolol but improved markedly after pindolol (p less than 0.005). Thus, while intravenous pindolol and metoprolol produced equal reductions in rate-pressure product, pindolol, a beta-adrenergic-blocking drug with intrinsic sympathomimetic activity, evoked less cardiac depression and thus provided a cardiac safety factor not afforded by the beta- 1-selective metoprolol.

Immediate detection of early high-risk patients with acute myocardial infarction using two-dimensional echocardiographic evaluation of left ventricular regional wall motion abnormalities

Forty-three patients with acute myocardial infarction (AMI) were studied with serial two-dimensional echocardiography (2DE) to define a high-risk subset for in-hospital cardiovascular complications including pump failure, life-threatening arrhythmias, or death. A 2DE segment score was developed representing the extent of left ventricular (LV) regional wall motion abnormality (WMA) which was correlated with peak total creatine kinase (CK) release. Patients with transmural AMI had a segment score of 7.2 +/- 3.8, whereas those with nontransmural AMI had a segment score of 4.7 +/- 3.4 (p less than 0.025). Peak total serum CK enzyme level correlated statistically with segment score but with a low correlation coefficient. Thirteen (30%) of the 43 patients had an in-hospital complication and their segment score was 10.0 +/- 3.4 compared to 4.6 +/- 2.7 in those patients without a complication (p less than 0.005). A segment score greater than or equal to 8 was found in 11 of 13 (85%) of those who suffered a cardiac complication and in only five (16%) of the 30 patients without complication (p less than 0.05; sensitivity 85%, specificity 83%). Patient's initial clinical Killip classification was specific but very insensitive in predicting an early complicated course. Thus, 2DE study of LV regional wall motion can predict in the immediate post-AMI stage the in-hospital likelihood of such patients developing a cardiovascular complication during acute myocardial infarction.

Immediate diagnosis of acute myocardial infarction by two-dimensional echocardiography

To define the role of portable two-dimensional echocardiography (2-D echo) in the immediate diagnosis of acute chest pain syndrome, 80 consecutive patients were studied. Adequate 2-D echo studies were obtained in 65 (81%). Thirty-three patients had clinical evidence of transmural or nontransmural acute myocardial infarction (AMI), 18 of whom had nondiagnostic initial ECGs. Thirty-two did not have a clinical AMI. Thirty-one of the 33 (94%) patients with clinical AMI had regional wall motion abnormalities on the initial 2-D echo; the other two had uncomplicated nontransmural AMIs, diagnosed only by ECG in one and by ECG and moderate elevation of CK-MB isoenzyme in the other. Twenty-seven of the 32 patients without clinical AMI had normal regional wall motion on the initial 2-D echo and none had a complication (severe arrhythmia, recurrent pain, heart failure or death) during the hospital course. Conversely, 10 of the 36 patients with initial 2-D echo regional wall motion abnormalities had a complication (p less than 0.05). Thus, in patients with acute chest pain syndrome, an initial 2-D echo that shows no regional wall motion abnormality suggests that such patients will not develop an AMI or clinical complication during the hospital course. An initial 2-D echo with regional wall motion abnormality identifies a high-risk group of patients who are likely to have AMI and important cardiac complications and may, therefore, benefit from admission to an intensive care unit.