Transesophageal echocardiographic assessment of systolic and diastolic dysfunction during percutaneous transluminal coronary angioplasty

Nicardipine or nitroglycerin in patients with failed percutaneous coronary angioplasty: effect on myocardial diastolic function

OBJECTIVE

To evaluate whether intracoronary vasodilators can improve diastolic function in 32 patients with failed percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Clinical trial.

SETTING

Single-institution, academic hospital.

PARTICIPANTS

Failed PTCA patients undergoing emergency coronary artery bypass grafting surgery.

INTERVENTIONS

Patients were divided into 2 groups: group A received 0.1 mg of intracoronary nicardipine, and group B received 20 microg of intracoronary nitroglycerin. Both drugs were administrated via a coronary dilatation perfusion catheter inserted in the catheterization laboratory by the cardiologist. Subsequently, they were continuously infused via the side port of the introducer of the pulmonary artery catheter and titrated to keep systolic blood pressure at about two thirds of the control value. Transesophageal echocardiography (Power Vision/6000, 9-mm 5MHZ Probe; Toshiba, Elmsford, NY) was used in this study.

MEASUREMENTS AND MAIN RESULTS

Left ventricular ejection fraction, cardiac index, tissue Doppler imaging velocity of the left ventricle and mitral annulus, and troponin levels were measured before and after administration of the 2 vasodilators and after cardiopulmonary bypass. Diastolic dysfunction was found preoperatively in all the patients and responded only to intracoronary nicardipine. Ea of mitral annulus velocity significantly increased in group A patients from 7.5 +/- 0.02 to 11.8 +/- 0.01 (p < 0.005) and decreased in group B patients from 8.0 +/- 0.03 to 7.5 +/- 0.02 after nicardipine or nitroglycerin administration. Left ventricular ejection fraction and cardiac index increased significantly (p < 0.005) only after nicardipine administration. Troponin levels were significantly lower in group A than in group B patients (p < 0.005).

CONCLUSION

Intracoronary nicardipine improves diastolic function and myocardial flow velocity in patients with failed PTCA undergoing emergency coronary artery bypass graft surgery.

Left ventricular electromechanical mapping: preliminary evidence of electromechanical changes after successful coronary intervention

BACKGROUND

Postinterventional ischemic myocardial dysfunction and its sequelae are still not well understood.

METHODS AND RESULTS

To gain further insight into the immediate physiologic consequences of coronary interventions and to better understand the nature of changes that result from such interventions, we analyzed 96 electromechanical maps from 48 patients before and after successful, uncomplicated percutaneous coronary interventions (PCI). A NOGA system was used to construct the map of the endocardial surface. Reproducibility was confirmed by constructing 10 additional maps in 5 patients who did not undergo an intervening procedure. Discordant areas were defined as those with preserved unipolar voltage (> or =7.5 mV) and diminished linear local shortening (< or =12.5%). On the basis of comparison of the variations in the discordance values (%) in the reproducibility group, patients were considered improved (lower values), worsened (higher values), or unchanged. In the reproducibility group, the mean variation in discordance was 2.18% +/- 1.26%, whereas in the PCI group, it was 21.97% +/- 18.47%. In the PCI group (rotational atherectomy subgroup [n = 10] and stent subgroup [n = 38]), left ventricular discordance values improved in 19 patients (39.6%), worsened in 24 (50%), and remained the same in 5 (10.4%). Of all variables analyzed, only abciximab was significantly associated with postintervention improvement in discordance (P =.02; odds ratio 0.165, 95% CI 0.03-0.88), regardless of the type of intervention performed (P =.61), whereas heparin alone was associated with more discordance after intervention (odds ratio 6.07, 95% CI 1.14-32.40).

CONCLUSIONS

We assessed the effect of percutaneous revascularization on myocardium by use of electromechanical data. For the first time, changes in linear local shortening in areas of preserved unipolar voltage were quantified, and worsening after successful Thrombolysis In Myocardial Infarction grade III coronary interventions was registered. The only variable associated with improvement on electromechanical data after interventions was the use of abciximab. This raises the question of the possible potential of this new diagnostic tool in assessing and quantifying postinterventional microvasculature pathological changes.

Acute changes in systolic and diastolic events during clinical coronary angioplasty: a comparison of regional velocity, strain rate, and strain measurement

Ultrasound-derived natural strain rate and strain are new Doppler myocardial imaging (DMI) parameters, which can measure local deformation independently of overall heart motion and thus could better characterize local contractility than DMI velocities alone. This study was undertaken to evaluate the relative benefits of regional velocity, strain rate, and strain measurements in detecting the range of acute changes in regional myocardial function in the "at-risk" zone during coronary angioplasty. Sixty-one patients (aged 63 +/- 12, 18 women) with stable angina pectoris were studied before, at the end of, and during recovery from a 60-second percutaneous transluminal coronary angioplasty (PTCA) balloon occlusion. High frame rate (147 fps) color DMI regional velocity data were derived from basal posterior (parasternal view) and mid, apical septal (apical view) "at-risk" segments as well as from the corresponding segments in healthy subjects and analyzed offline for velocity (VEL), strain rate (SR), and strain (epsilon) measurements. Coronary occlusion resulted in the reduction in VEL(SYS), SR(SYS), and epsilon(SYS) values for both radial (RCA/CX occlusion) and longitudinal data (LAD occlusion) in all segments analyzed. Velocity parameters alone failed to distinguish between baseline and occlusive measurements in the "at-risk" segments with visually abnormal baseline function. SR(SYS) and epsilon(SYS) had a higher diagnostic accuracy (sensitivity 75%, 80% and specificity 80%, 82%, respectively) than VEL(SYS) velocity alone (sensitivity 68%, specificity 65%,) for identifying acute ischemia in either baseline normal and abnormal segments. DMI-derived indexes can identify and quantify the spectrum of acute systolic and diastolic ischemic changes induced during clinical PTCA. The quantitation of regional deformation rather than motion would appear to be more appropriate in detecting and quantifying acute ischemic changes in myocardial function, especially in segments with pre-existing abnormal function.

Prognostic implications of restrictive left ventricular filling in acute myocardial infarction: a serial Doppler echocardiographic study

OBJECTIVES

This study was designed to evaluate the relative prognostic significance of restrictive left ventricular (LV) filling after acute myocardial infarction.

BACKGROUND

Data regarding the contribution of diastolic dysfunction to prognosis after myocardial infarction are limited, and the additional value over the assessment of systolic dysfunction is not known.

METHODS

Serial Doppler echocardiography was performed in 95 patients on days 1, 3 and 7 and 3 months after acute myocardial infarction. Patients were classified into two groups: a restrictive group (n = 12) with a peak velocity of early diastolic filling wave (E)/peak velocity of late filling wave (A) ratio > or = 2 or between 1 and 2 and a deceleration time (DT) < or = 140 ms during at least one echocardiographic study; and a nonrestrictive group (n = 83) with an E/A ratio < or = 1 or between 1 and 2 and a DT > 140 ms at all examinations.

RESULTS

Cardiac death occurred in 10 patients during a mean follow-up interval of 32 +/- 17 months. The survival rate at 1 year was 100% in the nonrestrictive group and only 50% in the restrictive group. After 1 year there was a continuing divergence of mortality, resulting in a 3-year survival rate of 100% and 22%, respectively. Univariate Cox analysis revealed that restrictive LV filling, wall motion score index, ejection fraction and end-systolic and end-diastolic volume indexes, as well as peak creatine kinase, peak MB fraction and heart failure during the hospital course were significant predictors of cardiac death, although restrictive filling was the single best predictor (p < 0.0001). Multivariate analysis showed that restrictive filling adds prognostic information to clinical and echocardiographic variables of systolic dysfunction.

CONCLUSIONS

Restrictive LV filling after acute myocardial infarction is the single best predictor of cardiac death and adds significantly to clinical and echocardiographic markers of systolic dysfunction.

Dynamics of left ventricular apex rotation during angioplasty: a sensitive index of ischemic dysfunction

BACKGROUND

Apex rotation has been shown to provide a reliable index of the dynamics of left ventricular (LV) twist. In this study, we aimed to characterize twist at baseline and during acute ischemia in 20 patients undergoing percutaneous transluminal coronary angioplasty to the left anterior descending (LAD) artery and to test whether an old myocardial infarction or collateral flow affected twist dynamics.

METHODS AND RESULTS

Among patients with no previous infarction, five had no collaterals (group A) and six had angiographically visible collaterals (group B). Previous anterior infarction was present in nine patients (group C). Data were acquired with the LAD angioplasty wire passed beyond the apex using a view aligned with the LV long axis. Frame-by-frame dynamics of apex rotation were measured from the angular movement of the portion of the wire that traversed the apex. Aortic pressure recordings allowed precise temporal definition of the cardiac cycle. Dynamics of apex rotation were measured at fixed intervals until 60 seconds of occlusion and up to 60 seconds of reperfusion. In group A, counterclockwise apex rotation (twist) during ejection of -22.0+/-1.7 degrees (mean+/-SEE) was followed by rapid clockwise rotation (untwist) during isovolumic relaxation. During 60 seconds of ischemia, maximum apex rotation decreased to -8.2+/-2.0 degrees (P<.001 versus baseline). In group B, baseline apex rotation was similar (-26.2+/-6.9 degrees) to that in group A, but ischemia had less effect, with apex rotation values of -17.7+/-3.4 degrees (P<.05 versus group A values). Group C was characterized by reduced baseline apex rotation values (-9.7+/-3.1 degrees, P<.05 versus group A values), with little change observed during ischemia (-8.1+/-2.6 degrees).

CONCLUSIONS

Apex rotation, an index of ventricular twist, is sensitive to acute ischemia in patients without previous myocardial infarction. Visible collaterals to the ischemic region attenuate the acute ischemic response at 60 seconds. Previous myocardial infarction causes abnormalities in the baseline twist pattern with no further deterioration at 60 seconds of ischemia.

The inverse Nehb J lead increases the sensitivity of Holter electrocardiographic monitoring for detecting myocardial ischemia

A major reason for the relatively low sensitivity of Holter electrocardiography (ECG) for detecting ischemia is that the sensitivity of bipolar leads used for Holter ischemia monitoring has not been systematically evaluated, making lead selection difficult. Therefore, this study evaluated the sensitivity of 6 bipolar Holter leads for detecting ischemia during percutaneous transluminal coronary angioplasty. Seventy-five patients, each of whom had > 1 mm ST-segment elevation on an intracoronary electrocardiogram from the myocardium distal to the stenosis during balloon occlusion, were studied for the occurrence of > or = 1 mm ST-segment elevation or depression on the simultaneously recorded Holter leads II, III, aVF, CM5, CR4, and inverse Nehb J. The study found that the inverse lead Nehb J provided a significantly higher overall sensitivity for detecting myocardial ischemia than Holter leads II, III, aVF, CM5, and CR4. Also, the use of inverse lead Nehb J significantly increased the sensitivity of 2- and 3-lead Holter ischemia monitoring. These findings were based on a significantly higher sensitivity of inverse lead Nehb J for detecting ischemia induced by transient occlusion of the left anterior descending coronary artery and a slightly higher sensitivity for detecting ischemia induced by occlusion of the left circumflex coronary artery. None of the bipolar leads studied provided a very high sensitivity for detecting ischemia induced by occlusion of the right coronary artery. These findings show that adequate lead selection can increase the sensitivity of Holter ischemia monitoring. Furthermore, the lack of a highly sensitive lead for detection of inferior ischemia indicates that further evaluation of bipolar leads is warranted.

A new scoring system, using Doppler transmitral diastolic measurement, identifies transient myocardial ischaemia

In patients with acute transient myocardial ischaemia, changes in left ventricular filling produce alterations in transmitral diastolic flow velocity and isovolumic relaxation time. In this study a scoring system derived from isovolumic relaxation time and indices from transmitral flow velocity was used to evaluate perioperative transient myocardial ischaemia. Fifty three patients with known coronary artery disease or at risk were studied. Ischaemic events were assessed using Doppler transoesophageal echocardiography midoesophageal left ventricular four-chamber view planes. Diastolic Doppler ratios of peak early to atrial peak (E/A), deceleration time, deceleration rate and isovolumic relaxation time were scored using standard methods. An evaluation of peri-operative ischaemic events could be important for patients with a non-ischaemic cause for abnormal segmental wall motion, as the use of a two-dimensional scoring system has limitations. Acute changes in the Doppler ratio of peak early to atrial peak must be interpreted cautiously during surgery. Diastolic dysfunction commonly occurs during ischaemia and recognition of this may alter the approach to monitoring as well as to treatment.

Influence of pacing-induced myocardial ischemia on left atrial regurgitant jet: a transesophageal echocardiographic study

OBJECTIVES

We investigated the influence of pacing-induced myocardial ischemia on systolic regurgitant jet in the left atrium, using simultaneous transesophageal echocardiography and transesophageal atrial pacing.

BACKGROUND

In vitro studies have shown that ischemia-induced mitral regurgitation may occur as a result of mitral leaflet malcoaptation or (global) left ventricular dysfunction. However, no transesophageal echocardiographic study has thus far been performed to demonstrate the mechanism and extent of mitral regurgitation during myocardial ischemia in patients.

METHODS

In 24 patients (mean [+/- SD] age 57 +/- 10 years) with (15 patients) and without (9 control subjects) coronary artery disease, heart rate, blood pressure and systolic regurgitant jet were assessed before and immediately after pacing. Pacing was increased stepwise up to 160 beats/min to provoke wall motion abnormalities while the left ventricular short axis was monitored at the midpapillary muscle level. Other variables obtained before and at peak pacing included left ventricular end-diastolic and end-systolic areas and left ventricular end-diastolic and end-systolic endocardial segmental lengths.

RESULTS

Heart rate and blood pressure before and after pacing were not significantly different in control subjects or in patients. At baseline, a jet was present in all but three control subjects. New or increased anterior or posterior wall motion abnormalities were observed during pacing in seven and eight patients, respectively. End-systolic left ventricular areas and segment lengths were significantly reduced in control subjects compared with patients with coronary artery disease at peak pacing (p < 0.05). The increase in systolic regurgitant jet was significantly greater in patients (2.0 +/- 1.1 to 3.1 +/- 1.8 cm2 vs. 0.7 +/- 0.7 to 0.9 +/- 0.9 cm2 [after pacing], p < 0.01). This effect was greater in patients with posterior than with anterior wall motion abnormalities (3.5 +/- 1.6 vs. 2.1 +/- 1.2 cm2 [after pacing], p < 0.05).

CONCLUSIONS

Quantitative changes in geometry and function of the left ventricle caused by pacing-induced myocardial ischemia augments systolic regurgitant jet size. An increase in the jet during atrial pacing is associated with new or increased wall motion abnormalities, especially of the posterior wall. Pacing-induced anterior wall motion abnormalities appear not to be related directly to an increase in the jet.

Usefulness of echocardiography and Doppler in the detection of segmental myocardial ischemia

Echocardiography and Doppler was performed in 20 patients during percutaneous transluminal coronary angioplasty of a right coronary artery to evaluate the usefulness of echocardiography and Doppler in the detection of segmental myocardial ischemia. Wall motion analysis was also compared to the occurrence of chest pain in relation to electrocardiographic and hemodynamic changes. Even in the case of small segmental myocardial ischemia, the two-dimensional echocardiographic evaluation of wall motion is superior to all other measured parameters. Contrary to this, the Doppler examination of transmitral flow is not sensitive enough in the detection of such small segmental myocardial ischemia, induced by right coronary artery occlusion.

Left Ventricular Diastolic Function

Two-dimensional echocafdiography has gained widespread acceptance I as the procedure of choice to evaluate left ventricular function. In the last decade, the importance of diastolic function in the overall performance of the left ventricle has received much attention. Recent evidence suggests that diastolic dysfunction may contribute to symptoms of left heart failure in many patients, including those with normal sys tolic function. Alterations in transmitral Dop pler flow velocity patterns have been used to assess changes in left ventricular diastolic func tion. This article reviews the concept and clin ical signincance of diastolic function and the assessment of diastolic function by Doppler echocardiography.

Echocardiographic detection of acute myocardial ischemia during percutaneous transluminal coronary angioplasty

The usefulness of echocardiography and Doppler for the detection of acute myocardial ischemia was evaluated during right coronary artery occlusion in 20 patients. The echocardiographic findings were compared with the occurrence of chest pain, and to electrocardiographic and hemodynamic changes obtained during percutaneous transluminal coronary angioplasty. Our results confirm that, even in the case of small segmental myocardial ischemia, two-dimensional echocardiography is superior to all other measured parameters. In contrast, Doppler examination of transmitral flow is not sensitive enough for the detection of such small segmental myocardial ischemia induced by right coronary artery occlusion.

Doppler assessment of left ventricular diastolic function: a review

Two-dimensional echocardiography provides valuable information for the assessment of left ventricular function. Traditionally, evaluation has focused on determination of systolic performance. However, recent investigations indicate diastolic dysfunction may also contribute to symptoms of congestive heart failure in many patients despite normal systolic function. Pulsed Doppler echocardiography complements two-dimensional imaging for assessment of left ventricular filling properties that are often altered in the setting of diastolic dysfunction. The concept of diastolic function and recognition of abnormal filling patterns detected by pulsed Doppler echocardiography are reviewed.

Utility of stress echocardiography for postinfarct prognosis

Although high-risk patients following myocardial infarct are usually identified in the acute stage by clinical assessment and determination of left ventricular function at rest, a significant percentage of infarct patients with increased risks, i.e., presence of residual myocardial ischemia, remain undetected at discharge. Since the yield of adequate images for interpretation stress echocardiograms has been significantly improved with digital technology, stress echocardiography has become a truly practical technique to identify these patients. Presence of remote asynergy, i.e., asynergy not directly adjacent to the infarcted area and supposed to be related to another vascular region, directly following cessation of dynamic exercise appears to be highly related to multivessel disease and an unfavorable follow-up period. Treadmill electrocardiographic findings, however, appeared to be of limited value in this respect. Furthermore, the echocardiographic ejection fraction was also a poor predictor. The versatility of the technique, lack of injections, or radiation hazard, and the relatively low cost will undoubtedly increase the application of stress echocardiography for postinfarct stratification.