Right ventricular myocardial infarction with anterior wall left ventricular infarction: an autopsy study

Early right ventricular dysfunction after primary percutaneous coronary intervention in anterior versus isolated inferior myocardial infarction assessed by tissue Doppler imaging and speckle tracking echocardiography

This study hypothesized that imaging provides information indicating the right ventricular (RV) involvement after anterior or inferior ST-elevation myocardial infarction (STEMI), beyond standard electrocardiogram (ECG) due to the increasing interest in RV function and assessment techniques. This study aimed to compare RV function between anterior and inferior MI without RV involvement using different echocardiographic modalities. This study included 100 patients with anterior (50 patients) and inferior (50 patients) STEMI, who underwent primary percutaneous coronary intervention (PPCI) and two-dimensional echocardiographic imaging within 24 h after PPCI with RV function analysis by left ventricular (LV) infarct size, LV filling pressure, and RV strain rate. Our primary endpoint was the subclinical RV dysfunction in anterior or inferior MI using tissue Doppler and speckle tracking (STE). The study population included 80 (80%) males and 20 (20%) females. Patients with the anterior STEMI had higher mean creatine kinase-MB (CKMB) and troponin than those with inferior STEMI. This study revealed worse RV dysfunction in patients with anterior than those with inferior STEMI, as reflected by significantly lower RV systolic function, tricuspid annular plane systolic excursion (p ≤ 0.0001), tissue Doppler-derived velocity (p ≤ 0.0001), and STE-derived strain magnitude and rate (p ≤ 0.0001). RV dysfunction occurs in patients without ECG evidence of RV STEMI. RV dysfunction is worse in anterior than inferior MI. Moreover, RV systolic functions were affected by declined LV ejection fraction irrespective of the infarction site, which clinically implies prognostic, treatment, survival rate, and outcome improvement between both conditions. (Trial registration ZU-IRB#:4142/26-12-2017 Registered 26 December 2017, email: IRB_123@medicine.zu.edu.eg).

Clinical characteristics and prognosis differences between isolated right and left ventricular myocardial infarction in the Chinese population: a retrospective study

Background and aims

Acute myocardial infarction (AMI) is divided into left ventricular myocardial infarction (LVMI) and right ventricular myocardial infarction (RVMI) according to the regions of myocardial ischemic necrosis. Clinical characteristics, treatment strategies, and prognosis differences between isolated RVMI and LVMI have not been well characterized. This study aimed to explore this difference of patients with isolated RVMI and LVMI.

Methods

This retrospective cohort study included 3,506 patients hospitalized with coronary angiography diagnosed type 1 myocardial infarction (MI). Characteristics of admission and treatment strategies were compared in patients with isolated RVMI and LVMI. COX proportional hazards models with and without inverse probability of treatment weighting (IPTW) adjustment were performed to estimate the difference in all-cause and cardiovascular mortality between the two groups.

Results

In this retrospective study, we found the frequency of isolated RVMI was significantly lower in the population than that of isolated LVMI (406 (11.6%) vs 3,100 (88.4%)). Patients with isolated RVMI have similar age, sex, and comorbidities to the patients with isolated LVMI. However, patients with isolated RVMI have lower heart rate and blood pressure, but higher rates of cardiogenic shock and atrioventricular block. It is noteworthy that patients with isolated RVMI are more likely to be complicated with the multivessel lesion. Patients with isolated RVMI have lower risk of all-cause mortality (HR 0.36; 95% CI [0.24-0.54], p < 0.001) and cardiovascular mortality (HR 0.37; 95% CI [0.22-0.62], p < 0.001) than patients with isolated LVMI.

Conclusions

This study showed that patients with isolated RVMI and LVMI have similar baseline characteristics. However, the clinical manifestations were different in the isolated RVMI and LVMI patients. This study revealed a better prognosis of isolated RVMI patients compared to isolated LVMI, which indicates the ischemic region could be considered in AMI risk stratification models for better assessment of risk for adverse clinical events.

Oozing-type rupture caused by right ventricular intramural hematoma after right ventricular infarction

An 81-year-old man was admitted to the hospital because of decreased level of consciousness. He had bradycardia (27 beats/min). Electrocardiography showed ST-segment elevation in leads II, III, and aVF and ST-segment depression in leads aVL, V1. Transthoracic echocardiography (TTE) visualized reduced motion of the left ventricular (LV) inferior wall and right ventricular (RV) free wall. Coronary angiography revealed occlusion of the right coronary artery. A primary percutaneous coronary intervention was successfully performed with temporary pacemaker backup. On the third day, the sinus rhythm recovered, and the temporary pacemaker was removed. On the fifth day, a sudden cardiac arrest occurred. Extracorporeal cardiopulmonary resuscitation was performed. TTE showed a high-echoic effusion around the right ventricle, indicating a hematoma. The drainage was ineffective. He died on the eighth day. An autopsy showed the infarcted lesion and an intramural hematoma in the RV. However, no definite perforation of the myocardium was detected. The hematoma extended to the epicardium surface, indicative of oozing-type RV rupture induced by RV infarction. The oozing-type rupture induced by RV infarction might develop asymptomatically without influence on the vital signs of the patient. Frequent echocardiographic evaluation is essential in cases of RV infarction taking care of silent oozing-type rupture.

Learning objective

Inferior left ventricular infarction sometimes complicates right ventricular (RV) infarction. The typical manifestations of RV infarction include low blood pressure, low cardiac output, and elevated right atrium pressure. Although the frequency is low, fatal complications of oozing-type RV rupture might progress asymptomatically. Frequent echocardiographic screening is necessary to detect them.

Right Ventricular Free Wall Rupture Complicating Anterior STEMI

Ventricular free wall rupture is a rare but devastating complication. We report right ventricular free wall rupture complicating anterior ST-segment elevation myocardial infarction caused by a wrap-around left anterior descending coronary artery. In acute cardiac tamponade, a rapid and systematic evaluation of the likely source of bleeding is paramount to prevent disastrous outcomes. (Level of Difficulty: Advanced.)

RIGHT VENTRICLE FUNCTION IN PATIENTS WITH ANTERIOR MYOCARDIAL INFARCTION: ARE WE SURE IT IS NOT INVOLVED?

The right and left ventricle of heart are intimately connected by anatomical and functional links. Hence, acute changes in cardiac geometry and function can modify the performance and physiology of both sides of the heart, influencing each other. After a brief overview of the anatomy and related imaging techniques for the study of right ventricular function, we report a review on the interesting correlation of acute anterior myocardial infarction and right ventricular function, very often underestimated.

CHARACTERIZATION OF THE RIGHT VENTRICULAR SUBSTRATE PARTICIPATING IN POST INFARCTION VENTRICULAR TACHYCARDIA

BACKGROUND

The right ventricle (RV) is uncommonly implicated in post-infarction ventricular tachycardia (VT). The prevalence and features of RV substrate participating in post-infarction VT are undefined.

OBJECTIVES

To characterize critical RV substrate (CRVS) involvement in patients with post-infarction VT.

METHODS

We retrospectively reviewed 1279 patients with post-infarction VT undergoing catheter ablation at our center from January 2000 through May 2020. Cases with CRVS defined by conclusive demonstration of participation in VT with activation, entrainment and/or pace mapping during sinus rhythm were identified.

RESULTS

CRVS was identified in 27/1279 (2.1%), age 65±13 years, 96% males, median LV EF 25%, 93% with LBBB morphology VT. CRVS was identified by RV activation and/or entrainment mapping (n=19) or by presence of low-voltage abnormal electrograms with excellent pace-map for the targeted VT and non-inducibility following ablation (n=8). VT termination during RV ablation occurred in 15 patients. After a median follow-up of 20 months (interquartile range 9-53 months) and a median of 2 procedures (interquartile range 1-3), 22/27 (80%) patients had no VT recurrence and 11 (41%) died.

CONCLUSION

The RV contains critical substrate elements of post-infarction VT in at least 2.1% of cases. RV mapping should be considered in cases where LV mapping fails to demonstrate adequate targets, particularly in patients with LBBB morphology VT.

Assessment of Right Ventricular Function in Patients With Acute Myocardial Infarction

Introduction

We assessed the right ventricular function in patients with first acute anterior wall myocardial infarction (AWMI) and inferior wall myocardial infarction (IWMI) without associated right ventricular infarction and assessed the relation between right ventricular function and the in-hospital clinical outcomes.

Methods

The present study was an observational cross-sectional study, which enrolled a total of 200 patients with chest pain of <24 hours who were diagnosed with acute ST-segment elevation myocardial infarction (MI) for the first time. Echocardiography was performed with a special emphasis on the tricuspid annular plane systolic excursion (TAPSE) score. The in-hospital clinical outcomes include major adverse cardiac events (MACE), which refer to all-cause mortality, cardiovascular mortality, recurrent MI, heart failure, or stroke in patients with acute myocardial infarction (AMI).

Results

A total of 200 patients with AMI were enrolled in the study of which 66% were males. Of patients, 68% had AWMI and 32% had IWMI. Patients with AWMI had more right ventricular dysfunctional changes as compared to IWMI, as measured by TAPSE score (17.8 ± 4.64 mm vs. 19.87 ± 3.61; p = 0.01, respectively). The incidence of MACE was 27.9% in AWMI as compared to 12.5% in IWMI (41.9% vs. 18.75% had right ventricular dysfunction, respectively). The outcome of AWMI patients was poor as compared to IWMI patients, as measured by duration of hospital stay (9.5 ± 4.73 days and 6.6 ± 4.70 days, respectively) and mortality (17.64% in AWMI vs. 6.25% in IWMI). The patients of AMI with TAPSE score ≤18 mm, suggesting right ventricular dysfunction, had a higher rate of MACE compared to those with TAPSE score >18 mm, respectively, 36.23% vs. 12.2%.

Conclusion

From this study, it is concluded that AWMI results in a higher incidence of right ventricular dysfunction as compared to IWMI. Furthermore, patients with AMI with concomitant right ventricular dysfunction were found to have poorer outcomes in terms of longer duration of hospital stay, higher incidence of MACE, and higher mortality rate, as compared to patients of AMI without right ventricular dysfunction.

Right ventricular dysfunction and long-term risk of death

Sudden cardiac death (SCD), or sudden loss of life-sustaining systemic and cerebral perfusion, is most often due to left ventricular (LV) dysfunction secondary to ischemic or structural cardiac disease or channelopathies. Degeneration of sinus rhythm into ventricular tachycardia and ultimately ventricular fibrillation is the final common pathway for most heart failure patients. Right ventricular (RV) dysfunction is recognized as an independent contributor to worsening heart failure. There is emerging evidence that RV dysfunction may also be an independent predictor of SCD. This review examines the role of RV dysfunction on modifying long term risk of SCD, and explores possible mechanisms that may underlie SCD. The RV has unique anatomy and physiology compared to the LV. Subsequently, we begin with a review of cardiac embryology, focusing on the chambers, valves, coronary arteries, and cardiac conduction system to understand the origins of RV dysfunction. Static and dynamic physiology of the RV is contrasted with that of the LV. Particular emphasis is placed on ventriculo-arterial coupling, mechanical cardiac constraint, and ventricular interdependence. The epidemiology of SCD is briefly reviewed to highlight how causes of SCD are age-specific. In turn, the age-specific causes of RV dysfunction are presented, including those which predominate in childhood and adolescence [arrhythmogenic RV dysplasia (ARVD) and hypertrophic cardiomyopathy (HCM)] and older adulthood (cardiac ischemia, chronic congestive heart failure and post-capillary pulmonary hypertension, and pulmonary hypertension). There is a clear need for additional studies on the independent contribution of RV dysfunction to overall functional capacity, SCD-associated mortality, and non-SCD-associated mortality. Discovery would be aided by the development of prospective cohorts with excellent RV phenotyping, coupled with deeper biologic measurements linking mechanisms to clinically relevant outcomes.

Acute right ventricular myocardial infarction

INTRODUCTION

Acute right ventricular myocardial infarction (RVMI) is observed in 30-50% of patients presenting with inferior wall myocardial infarction (MI) and, occasionally, with anterior wall MI. The clinical consequences vary from no hemodynamic compromise to severe hypotension and cardiogenic shock depending on the extent of RV ischemia. Areas covered: The pathophysiological mechanisms, diagnostic steps, and novel therapeutic approaches of acute RVMI are described. Expert commentary: Diagnosis of acute RVMI is based on physical examination, cardiac biomarkers, electrocardiography, and coronary angiography, whereas noninvasive imaging modalities (echocardiography, cardiac magnetic resonance imaging) play a complementary role. Early revascularization, percutaneous or pharmacological, represents key step in the management of RMVI. Maintenance of reasonable heart rate and atrioventricular synchrony is essential to sustain adequate cardiac output in these patients. When conventional treatment is not successful, mechanical circulatory support, including right ventricle assist devices, percutaneous cardiopulmonary support, and intra-aortic balloon pump, might be considered. The prognosis associated with RVMI is worse in the short term, compared to non-RVMI, but those patients who survive hospitalization have a relatively good long-term prognosis.

The Role of Echocardiography in Acute Myocardial Infarction

The indications for echocardiography in the setting of acute myocardial infarction are to identify wall motion abnormalities, to evaluate left and right ventricular function, and to exclude complications such as pericarditis, mitral regurgitation, and ventricular rupture. Doppler echocardiography can provide important hemodynamic information. In the near future, contrast echocardiography can be expected to delineate myocardial perfusion and three-dimensional echocardiography to better define infarct size.

Association of the right ventricle impairment with electrocardiographic localization and related artery in patients with ST-elevation myocardial infarction

INTRODUCTION

The right ventricular myocardial infarction (RVMI) has traditionally been mainly related to inferior wall ST elevation myocardial infarction (STEMI). This study assessed the RVMI electrocardiographic (ECG-RVMI) signs in relationship to ECG-based STEMI localization and to the infarct related artery in patients treated with primary percutaneous coronary intervention (pPCI).

METHODS

Three hundred consecutive adult patients (107 females) were referred to catheterization laboratory with the acute STEMI diagnosis. In all patients, both the standard 12-lead ECGs and the right-sided precordial leads (V1R-V6R) were recorded. ECG-RVMI was diagnosed by ST segment elevation above 100μV in V4R.

RESULTS

ECG signs of RVMI were found in 35 and 31 (23.8% for both) patients with inferior and anterior wall STEMI, respectively. In 32 ECG-RVMI patients, the right coronary artery (RCA) was occluded while in 34 patients, the occlusions were in the left anterior descending (LAD) or the left circumflex artery. No statistically significant differences were found in ECG-RVMI patients when comparing clinical variables between those with anterior and inferior wall STEMI.

CONCLUSIONS

ECG signs of RVMI during acute STEMI are not uncommon. RCA was the infarction-related artery in only one half of these patients. Anterior wall STEMI and the LAD were associated with a significant proportion of ECG-RVMI cases.

The effects of urgent percutaneous coronary intervention on right ventricular systolic functions in non-ST-elevation acute coronary syndromes

BACKGROUND

Although the importance of the right ventricle (RV) involvement has been known for many years in patients with ST-elevation myocardial infarction (STEMI), it is scarce in non-ST-elevation acute coronary syndrome (NSTE-ACS).

OBJECTIVES

We aimed to investigate the effects of urgent percutaneous coronary intervention (PCI) on the RV systolic functions in patients with NSTE-ACS.

MATERIALS AND METHODS

Ninety-five patients diagnosed with NSTE-ACS and who underwent urgent PCI were prospectively investigated. RV systolic functions were analyzed and compared before and after PCI in all patients by using RV index of myocardial performance (RIMP), tricuspid annular plane systolic excursion (TAPSE), two-dimensional (2D) RV fractional area change (FAC), and isovolumic acceleration (IVA) parameters with transthoracic echocardiography.

RESULTS

Among 95 NSTE-ACS patients, 31 had impaired RIMP, 13 had impaired TAPSE, 8 had decreased 2D FAC, and 32 had impaired IVA values at baseline. There was a significant increase in 2D FAC and IVA values after PCI.

CONCLUSIONS

The right ventricular functions may also be affected in patients with NSTE-ACS, and urgent PCI has a significant effect on the recovery of right ventricular systolic functions in patients with NSTE-ACS.

Microvascular obstruction in the right ventricle in reperfused anterior myocardial infarction. Macroscopic and pathologic evidence in a swine model

INTRODUCTION

Data on right ventricular (RV) involvement in anterior myocardial infarction are scarce. The presence of RV microvascular obstruction (MVO) in this context has not been analyzed yet. The aim of the present study was to characterize the presence of MVO in the RV in a controlled experimental swine model of reperfused anterior myocardial infarction.

MATERIALS AND METHODS

Left anterior descending (LAD) artery-perfused area (thioflavin-S staining after selective infusion in LAD artery), infarct size (lack of triphenyltetrazolium-chloride staining) and MVO (lack of thioflavin-S staining in the core of the infarcted area) in the RV were studied. A quantitative (% of the ventricular volume) and semiquantitative (number of segments involved) analysis was carried out both in the RV and LV in a 90-min left anterior descending balloon occlusion and 3-day reperfusion model in swine (n=15).

RESULTS

RV infarction and RV MVO (>1 segment) were detected in 9 (60%) and 6 (40%) cases respectively. Mean LAD-perfused area, infarct size and MVO in the RV were 33.8 ± 13%, 13.53 ± 11.7% and 3.4 ± 4.5%. Haematoxylin and eosin stains and electron microscopy of the RV-MVO areas demonstrated generalized cardiomyocyte necrosis and inflammatory infiltration along with patched hemorrhagic areas. Ex-vivo nuclear magnetic resonance (T2 sequences) microimaging of RV-MVO showed, in comparison with remote non-infarcted territories, marked hypointense zones (corresponding to necrosis, inflammation and hemorrhage) in the core of hyperintense regions (corresponding to edema).

CONCLUSIONS

In reperfused anterior myocardial infarction, MVO is frequently present in the RV. It is associated with severe histologic repercussion on the RV wall. Nuclear magnetic resonance appears as a promising technique for the noninvasive detection of this phenomenon. Further studies are warranted to evaluate the pathophysiological and clinical implications.

Extent of RV dysfunction and myocardial infarction assessed by CMR are independent outcome predictors early after STEMI treated with primary angioplasty

OBJECTIVES

The aim of this study was to assess the prognostic value of right ventricular (RV) involvement diagnosed by cardiac magnetic resonance (CMR) early after ST-elevation myocardial infarction (STEMI).

BACKGROUND

CMR allows accurate and reproducible RV assessment. However, there is a paucity of data regarding the prognostic value of RV involvement detected by CMR early after STEMI.

METHODS

Ninety-nine patients (77 men, mean age 57 ± 11 years) who underwent CMR 3 to 5 days after STEMI treated with primary angioplasty were followed for 1,150 ± 337 days for cardiac events (cardiac death, nonfatal myocardial infarction [MI], and hospitalizations due to decompensated heart failure). Cox proportional hazards model was applied in stepwise forward fashion to identify outcome predictors. Event-free survival was estimated by Kaplan-Meier method and compared between groups by the log-rank test.

RESULTS

Cardiac events occurred in 34 patients (7 cardiac deaths, 8 MIs, 26 hospitalizations). By multivariable analysis, the independent outcome predictors were left ventricular (LV) MI transmurality index (hazard ratio: 1.03 per 1%; 95% confidence interval: 1.01 to 1.04; p = 0.001), RV ejection fraction (RVEF) (hazard ratio: 1.46 per 10% decrease; 95% confidence interval: 1.05 to 2.02; p = 0.03), and RVMI extent (hazard ratio: 1.50 per each infarcted RV segment; 95% confidence interval: 1.11 to 2.01; p = 0.007). Compared with clinical data (global chi-square = 5.2), LV ejection fraction [LVEF] (global chi-square = 11.1), RVEF (global chi-square = 17.1), LVMI transmural extent (global chi-square = 26.0), and RVMI extent (global chi-square = 34.9) improved outcome prediction in sequential Cox model analysis (p < 0.05 for all steps). RVEF stratified risk in patients with LVEF <40% in whom the 4-year event-free survival was 66.7% for RVEF ≥40% and 40.0% for RVEF <40% (p < 0.05).

CONCLUSIONS

The extent of RVMI and RV dysfunction assessed early after STEMI are independent outcome predictors, which provide incremental prognostic value to clinical data, LV systolic function, and infarct burden. Measurement of RVEF may be particularly useful to stratify risk in patients with depressed LV function after STEMI.

Right ventricular involvement in anterior myocardial infarction: a translational approach

AIMS

The aim of the present study was to evaluate the involvement of the right ventricle (RV) in reperfused anterior ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

Left anterior descending (LAD)-perfused area (using thioflavin-S staining after selective infusion in proximal LAD artery, %), infarct size (using triphenyltetrazolium chloride staining, %), and salvaged myocardium (% of LAD-perfused area) in the right and left ventricle (LV) were quantified in a 90-min LAD occlusion 3-day reperfusion model in swine (n = 8). Additionally, we studied, using cardiovascular magnetic resonance, 20 patients with a first STEMI due to proximal LAD occlusion treated with primary angioplasty. Area at risk (T2-weighted sequence, %), infarct size (late enhancement imaging, %), and salvaged myocardium (% of area at risk) in the right and LV were quantified. In swine, a large LAD-perfused area was detected both in the right and LV (30 +/- 5 vs. 62 +/- 15%, P< 0.001) but more salvaged myocardium (94 +/- 6 vs. 73 +/- 11%, P< 0.001) resulted in a smaller right ventricular infarct size (2 +/- 1 vs. 16 +/- 5%, P< 0.001). Similarly, in patients a large area at risk was detected both in the right and LV (34 +/- 13 vs. 43 +/- 12%, P = 0.02). More salvaged myocardium (94 +/- 10 vs. 33 +/- 26%, P < 0.001) resulted in a smaller infarct size (2 +/- 3 vs. 30 +/- 16%, P< 0.001) in the RV.

CONCLUSION

In reperfused extensive anterior STEMI, a large area of the RV is at risk but the resultant infarct size is small.

Impact on hospital mortality and morbidity of right ventricular involvement among patients with acute left ventricular infarction

CONTEXT AND OBJECTIVE

There is uncertainty regarding the risk of major complications in patients with left ventricular (LV) infarction complicated by right ventricular (RV) involvement. The aim of this study was to evaluate the impact on hospital mortality and morbidity of right ventricular involvement among patients with acute left ventricular myocardial infarction.

DESIGN AND SETTING

Prospective cohort study, at Emergency Care Unit of Hospital Central da Irmandade da Santa Casa de Misericórdia de São Paulo.

METHODS

183 patients with acute myocardial infarction participated in this study: 145 with LV infarction alone and 38 with both LV and RV infarction. The presence of complications and hospital death were compared between groups.

RESULTS

21% of the patients studied had LV + RV infarction. In this group, involvement of the dorsal and/or inferior wall was predominant on electrocardiogram (p < 0.0001). The frequencies of Killip class IV upon admission and 24 hours later were greater in the LV + RV group, along with electrical and hemodynamic complications, among others, and death. The probability of complications among the LV + RV patients was 9.7 times greater (odds ratio, OR = 9.7468; 95% confidence interval, CI: 2.8673 to 33.1325; p < 0.0001) and probability of death was 5.1 times greater (OR = 5.13; 95% CI: 2.2795 to 11.5510; p = 0.0001), in relation to patients with LV infarction alone.

CONCLUSIONS

Patients with LV infarction with RV involvement present increased risk of early morbidity and mortality.

High rate of right ventricular infarction after ligation of mid left anterior descending artery in rats

BACKGROUND

The left anterior descending artery (LAD) supplies the left ventricle in humans. LAD ligation has been commonly used in rats to induce left ventricular (LV) infarction for research purposes. However, the myocardial supply territories of LAD are not well established in rats. We measured the infarction zone in rats after ligation of the mid-LAD.

METHODS

Twenty-four male Sprague-Dawley rats weighing 300-350 g were selected for LAD ligation for the induction of ischemic cardiomyopathy. The surgery was performed under full anesthesia. Left-sided thoracotomy was performed through cuts in the fifth and sixth ribs. Ligation of the LAD was performed 1 to 2 mm distal to a line between the left border of the pulmonary conus and the right border of the left atrial appendage. LAD was ligated after the first diagonal and septal branches. After 24 h, the hearts were removed and stained with Tetrazolium Tetrachloride (TTC) for the detection of infracted areas.

RESULTS

Ligation of LAD induces 85% infarction of the right anterior free wall and anterior right ventricular septum and induces 100% infarction of the anterior free wall of the left ventricle and anterior septum. Infarction after LAD ligation extends all the way to the distal of the ligation site down to the apex of the heart.

CONCLUSIONS

Mid-LAD ligation after the first septal and diagonal branches causes substantial right ventricular infarction in addition to LV infarct in rats. Therefore, the hemodynamic effect of right ventricle infarct should be considered in research involving LAD ligation in rats.

Association Between A/C1166 Gene Polymorphism of the Angiotensin II Type 1 Receptor and Biventricular Functions in Patients With Acute Myocardial Infarction

BACKGROUND

Although there have been several association studies of angiotensin II type 1 receptor (AT1R, A/C1166) gene polymorphism in clinical endpoints such as myocardial infarction (MI), hypertension, aortic stiffness, and left ventricular mass, the relationship between AT1R polymorphism and biventricular function in acute anterior MI has not been studied before.

METHODS AND RESULTS

The study group comprised 132 consecutive patients who were admitted to the coronary care unit with their first acute anterior MI. Systolic and diastolic diameters, volumes, inflow properties, ejection fraction and myocardial performance index of both ventricles were measured. AT1R polymorphism was determined using polymerase chain reaction amplification. Based on A/C1166 polymorphism of AT1R, the patients were classified into 3 groups: group 1, A/A (n=91) genotype, group 2 A/C (n=28), and group 3 C/C (n=13) genotype. When the left ventricular and right ventricular echocardiographic functions were compared, all parameters of the 3 groups were found to be similar. No difference was detected in either the genotype distribution or allele frequencies between the patients and the controls for AT1R.

CONCLUSIONS

The results suggest that A/C1166 polymorphism of AT1R did not influence the risk of either acute MI or biventricular function after anterior MI.

Severe hypoxemia in a patient with acute myocardial infarction

A case report of a patient with acute myocardial infarction and severe hypoxemia due to acute right to left interatrial shunt (RLIAS) is presented. Diagnostic and therapeutic procedures are discussed.

Cardiogenic shock: predictors of outcome based on right and left ventricular size and function at presentation

OBJECTIVE

To determine the characteristics and prognostic importance of right ventricular (RV) dilatation and dysfunction in patients with cardiogenic shock secondary to left ventricular (LV) dysfunction enrolled in the Should we emergently revascularize occluded coronaries for cardiogenic shock (SHOCK) trial.

METHODS

LV and RV size and function were quantified by echocardiography in 99 patients with cardiogenic shock secondary to predominant LV dysfunction.

RESULTS

For all patients, RV dysfunction was not associated with a poor 1-year survival. When the 59 patients with RV dysfunction were stratified into two morphologic groups based upon LV-to-RV end-diastolic area ratio (LV/RV) < or >or=2, the presence of disproportionate RV enlargement (LV/RV <2) was associated with inferior myocardial infarction (80%) and right coronary artery culprit disease (79%). In contrast, the index myocardial infarction in patients with predominant LV enlargement (LV/RV >or=2) was anterior (69%) and associated with left anterior descending artery disease (64%). Patients with LV/RV <2 had significantly higher right atrial pressures (20.1+/-5.2 compared with 14.5+/-8.9 mmHg, P=0.001) and lower RV fractional area change (20.4+/-8.7 compared with 33.5+/-11.0%, P=0.0001), heart rate (87+/-21 compared with 106+/-23 beats/min, P=0.006) and cardiac index (1.5+/-0.5 compared with 2.0 +/-0.9 l/min per m, P=0.007) than patients with LV/RV >or=2. Despite the hemodynamic profile and severity of RV dysfunction in the LV/RV <2 group, 12-month survival was significantly greater in these patients (70% LV/RV <2 compared with 34% LV/RV >or=2, P=0.027).

CONCLUSIONS

In patients with cardiogenic shock secondary to predominant LV failure, the presence of RV dilatation and dysfunction identifies a subgroup of patients with predominant inferior myocardial infarction and an improved long-term prognosis.

Percutaneous atrial septostomy for urgent palliative treatment of severe refractory cardiogenic shock due to right ventricular infarction

We report a novel palliative treatment to improve refractory cardiogenic shock due to right ventricular ischemia. We performed percutaneous atrial septostomy to create an atrial septal defect, which resulted in immediate right ventricular decompression and increased left ventricular filling associated with prompt and dramatic hemodynamic and clinical improvement.

Clinical utility of ST-segment depression in lead AVR in acute myocardial infarction

The present study evaluated the prevalence and significance of ST-segment depression (STD) in lead aVR on the admission 12-lead electrocardiogram in 307 consecutive patients with an acute myocardial infarction (AMI) with ST-segment elevation. STD in aVR was present in a significantly higher proportion of patients with inferior/posterior AMIs. Within inferior/posterior AMIs those with STD in aVR had significantly more concomitant STD in V(1), V(2), V(3) and more concomitant STesegment elevation in V(5), V(6) and right precordial leads. These data suggests that STD in aVR may point to a coronary artery with a large area of supply as the culprit vessel responsible for the AMI.

Electrocardiographic manifestations: right ventricular infarction

The 12-lead electrocardiogram (EKG) is an essential tool when evaluating the Emergency Department (ED) patient with suspected cardiac ischemia. The standard EKG has limitations when evaluating "remote" areas of the heart such as the left posterior wall or right ventricular wall. Diagnosis of right ventricular infarction (RVI) in the presence of acute inferior wall myocardial infarction (MI) is made utilizing right-sided chest leads with high sensitivities and specificities. RVI is a serious ED problem because morbidity and mortality is higher in acute MIs associated with RVI.

Perfusion of myocardial segments of the right ventricle: role of the left coronary artery in infarction of the right ventricle

In a series of 88 human hearts, from individuals aged between 24 h and 94 yr (x= 61.09 +/- 21.96), the coronary arterial distribution of the right ventricle was studied using a modified Selvester's system of segmentation. Postmortem angiographies and microdissection techniques were used. The analysis of the six segments of the right ventricle shows that the three anterior segments, basal, mesial, and--less frequently--apical, present a type of irrigation that is practically constant and is dual. The postero-basal and postero-mesial segments are irrigated almost exclusively by the right coronary artery. In the remaining segments the vascularization was of mixed type, although a considerable degree of exclusive arterial perfusion was observed in the antero-apical segment. The segmental analysis allows us to conclude that although arterial vascularization of the right ventricle depends fundamentally on the right coronary artery, the anterior interventricular artery irrigates more than 20% of the right ventricular myocardium. Results from segmental analysis are compared with data from clinical and necropsic studies.

Arterial vascularization of the human moderator band: an analysis of this structure's role as a collateral circulation route

In the human heart, the moderator band, or trabecula septomarginalis, is a muscle column that courses inferiorly from the right portion of the interventricular septum to the base of the anterior papillary muscle of the right ventricle This muscular structure is crossed by one or more arteries, which come from the anterior interventricular artery and perfuses the anterior papillary muscle of the right ventricle. In order to clarify the arterial supply of this muscle column, we studied 28 adult hearts, free of any signs of coronary disorder. The path of the moderator band artery was followed by means of microdissection, and we studied the source, course, and interconnections made with other arteries. We observed that the source of the moderator band artery lies in the first three anterior septal arteries, most often in the second one. In relation to the short axis of the heart, the artery of the moderator band can either follow a horizontal path to the septal papillary muscle of the right ventricle or an oblique route to the moderator band, depending on the position of its source. In all the hearts studied, the moderator band artery made anastomotic connections at the base of the anterior papillary muscle of the right ventricle with various branches of the right coronary artery, which means that it can play a key role in collateral circulation following obstruction of the epicardium coronary arteries.

Right ventricular infarction associated with anteroseptal myocardial infarction: a clinicopathologic study of nine cases

The association of right ventricular (RV) infarction with inferoseptal myocardial infarction is well established. However, a question remains about the occurrence of RV infarction in association with anteroseptal myocardial infarction. To determine the frequency and clinical correlates of this entity, we studied autopsied hearts from patients with isolated anteroseptal left ventricular (LV) infarcts. Among 3,249 autopsy specimens, 88 cases were identified. From each, sections were taken from the RV anterior, lateral, and inferior regions at basal, middle, and apical levels. All 1,584 slides were reviewed by blinded assessment. RV and LV infarcts were compared to confirm similarity in age. Patient records and cardiac investigations were reviewed for evidence of RV involvement. Of the 88 hearts with anteroseptal LV infarcts, 9 (10%) had coexistent RV infarction (6, old; 3, new). For these 9, the RV infarction involved 11% to 33% of the RV area, and the left anterior descending coronary artery was the infarct-related artery in each. All 3 patients who had an echocardiographic examination within 4 weeks of anteroseptal LV infarction had RV dysfunction. One patient, studied 15 years after infarction, had a normal right ventricle by echocardiography. In 3 patients with acute myocardial infarction, right heart catheterization during the acute phase revealed increased right-sided diastolic pressures out of proportion to left-sided diastolic pressures (right atrial pressure to pulmonary capillary wedge pressure, 60% to 95%). In conclusion, 10% of patients with an isolated anteroseptal LV infarct had evidence of RV free wall infarction. The RV infarction was associated with identifiable hemodynamic and echocardiographic features.

Association between preinfarction angina and a lower risk of right ventricular infarction

BACKGROUND

Right ventricular infarction occurs in conjunction with inferior myocardial infarction caused by proximal occlusion of the right coronary artery. However, right ventricular infarction occurs infrequently, and the reasons for this are uncertain.

METHODS

We retrospectively assessed the association between preinfarction angina and right ventricular infarction, as well as the short-term outcome, in 113 patients with a first acute inferior myocardial infarction caused by right-coronary-artery occlusion. The association between the timing of angina during the week before infarction and the clinical outcome was also assessed.

RESULTS

The absence of preinfarction angina predicted the development of right ventricular infarction (odds ratio, 6.3; 95 percent confidence interval, 2.7 to 15.1; P<0.001), complete atrioventricular block (odds ratio, 3.6; 95 percent confidence interval, 1.4 to 10.3; P=0.01), and combined hypotension and shock (odds ratio, 12.4; 95 percent confidence interval, 4.5 to 40.6; P<0.001). Angina 24 to 72 hours before infarction was most strongly associated with reductions in the rates of right ventricular infarction (adjusted odds ratio, 0.2; 95 percent confidence interval, 0 to 0.8; P=0.02) and combined hypotension and shock (adjusted odds ratio, 0.1; 95 percent confidence interval, 0 to 0.5; P=0.02).

CONCLUSIONS

Preinfarction angina was an independent predictor of the absence of right ventricular infarction in patients with acute inferior myocardial infarction. The patients with preinfarction angina also had better short-term outcomes than those without preinfarction angina.

Marked dilutional acidosis complicating management of right ventricular myocardial infarction

Dilutional acidosis is a poorly recognized cause of metabolic acidosis. Indeed, the prevailing view has been that even massive expansion of the extracellular fluid volume with non-bicarbonate-containing solutions would not lead to clinically significant hypobicarbonatemia. We describe the development of marked dilutional acidosis as a complication of management of right ventricular myocardial infarction. The pathogenesis, clinical significance, prevention, and treatment of the entity are discussed.

Importance of the conal branch of the right coronary artery in patients with acute anterior wall myocardial infarction: electrocardiographic and angiographic correlation

OBJECTIVES

This study assessed prospectively the correlation between the conal branch of the right coronary artery and the pattern of ST segment elevation in leads V1 and V3R during anterior wall acute myocardial infarction (AMI).

BACKGROUND

The traditional electrocardiographic (ECG) definition of anteroseptal AMI-ST segment elevation in leads V1 to V3-has recently been challenged. The significance of ST segment elevation in lead V1 during anterior wall AMI is unclear.

METHODS

The admission 12-lead ECG with additional lead V3R and the coronary angiograms performed within 10 days of hospital admission were evaluated in 28 consecutive patients (mean age +/- SD 62 +/- 9 years) admitted to the coronary care unit with anterior wall AMI. Patients were classified into two groups according to the magnitude of ST segment elevation in lead V1: group A (elevation > or = 1.5 mm, n = 12) and group B (elevation < 1.5 mm, n = 16). Two types of conal branch were identified: small (not reaching the interventricular septum [IVS]) and large (reaching the IVS).

RESULTS

ST segment elevation in lead V3R was found in 11 (92%) and 6 (37%) patients from group A and group B, respectively (p < 0.001); a small conal branch was seen in 10 (83%) and 3 (19%) patients, respectively (p < 0.001). Ten patients (all from group B) had a large conal branch.

CONCLUSIONS

ST segment elevation in lead V1 in the admission ECG of patients with anterior wall AMI is strongly related to ST segment elevation in lead V3R and is associated with a small conal branch. Our findings suggest that lead V1 reflects the right paraseptal area supplied by the septal branches of the left anterior descending coronary artery (LAD), alone or together with the conal branch. The absence of ST segment elevation in lead V1 during anterior AMI suggests that the IVS is protected by a large conal branch in addition to the septal branches of the LAD (double circulation).

A new experimental model of isolated myocardial ischemic injury: ECG findings of acute isolated right ventricular ischemic injury

A new experimental porcine model for creating selective ischemia of a specific part of the myocardium while the rest of the myocardium remains free of ischemia has been used to study the electrocardiographic (ECG) changes deriving from selective ischemia of the right ventricular (RV) free wall. A patch was stitched to the ventricle to produce selective myocardial ischemic injury. In a preliminary study of nine pigs, selective ischemia of the left ventricular free wall in five and of the RV free wall in four animals was induced, and a postmortem dye injection was performed to evaluate blood flow in the area of ischemia. In an ECG study of 20 pigs, the baseline ECG was recorded with use of the standard leads I-III, aVR, aVL, and aVF, left precordial leads (V1-V6), and leads V4R, V3H, and V4H and 1 hour after inducing ischemia, the ECG study was repeated. Our experimental model produced ischemic injury in which the location and surface area were known antemortem. In the 20 pigs, ST-segment changes were recorded in leads V1-V3, V3H, and V4H. In only four pigs (20%) was ST-segment elevation recorded in lead V4R. The results show that the ECG signs of selective ischemia of the RV free wall may imitate the signs of anterior or anterolateral infarction of the left ventricle. In this study, elevation of the ST-segment in lead V4R was not pathognomonic of for RV ischemia. This model is a new tool for studying hemodynamic and ECG changes of selective univentricular or biventricular ischemic injury.

Serial changes in regional right ventricular free wall and left ventricular septal wall lengths during the first 4 to 5 years after index anterior wall myocardial infarction

OBJECTIVES

This study investigated serial changes in regional right ventricular free wall and interventricular septal wall lengths during the first 4 to 5 years after an index anterior wall myocardial infarction.

BACKGROUND

We previously demonstrated that remodeling after anterior wall myocardial infarction was a biventricular process; however, regional changes in biventricular topology were not investigated.

METHODS

Serial electron beam computed tomographic scanning was performed in 19 patients at five times (hospital discharge and at 6 weeks, 6 months, 1 year and 4 to 5 years) after an index anterior wall myocardial infarction, and global and regional right ventricular free wall and interventricular septal wall lengths were quantified.

RESULTS

At a mean (+/- SD) of 1,642 +/- 171 days (4 to 5 years) after infarction, global end-diastolic and end-systolic right ventricular free wall and interventricular septal wall lengths increased in parallel by 13% to 23% as global left and right ventricular volumes increased 22% to 29% from hospital discharge to 4 to 5 years after infarction. When global right ventricular free wall was compared with interventricular septal wall lengths, percent increases at end-diastole and end-systole were not statistically different at any time during the study period. Distinct regional changes in both right ventricular free wall and interventricular septal wall lengths after infarction were most dramatic during the first 6 weeks and primarily confined to the most apical levels. However, further and significant increases in both were observed by 4 to 5 years after infarction.

CONCLUSIONS

Changes in both right ventricular free wall and interventricular septal wall lengths were apparent during the 4 to 5 years after the index anterior wall infarction, and the combination of both contributed to global increases in right and left ventricular chamber volumes. Regional changes in both right ventricular free wall and interventricular septal wall lengths were almost exclusively confined to their respective apices and progressed generally in parallel; however, the cause-and-effect relation remains speculative at the present time.

Successful repair of combined septal and biventricular free wall rupture after acute myocardial infarction

The following case is the first report of successful repair of combined left and right ventricular free wall and ventricular septal rupture. Reports of left ventricular free wall and septal rupture and reports of right ventricular free wall and septal rupture have been published both with and without successful surgical repair. This case demonstrates the presence of left and right ventricular free wall rupture along with septal rupture based upon cardiac catheterization and operative findings. In spite of her severe mechanical complications and prolonged hospital course, the patient is completely functional 1 year after surgical repair.

Relations between Doppler tracings of pulmonary regurgitation and invasive hemodynamics in acute right ventricular infarction complicating inferior wall left ventricular infarction

To test the hypothesis that flow characteristics from pulmonary regurgitation (PR) can predict right ventricular (RV) involvement in patients with inferior wall acute myocardial infarction, we prospectively recorded continuous-wave Doppler tracings and right-sided cardiac hemodynamics in 48 consecutive patients with inferior wall acute myocardial infarction and PR. Right heart hemodynamics enabled the identification of 29 patients with (group 1) and 19 without (group 2) RV involvement. In patients with RV involvement, the pulmonary regurgitant flow pattern was characterized by a rapid rise in flow velocity to a peak level followed by an abrupt deceleration in mid-diastole, whereas in patients without RV involvement, the deceleration in mid-diastole was gradual. The pressure half-time of PR (PHTPR) and the lowest mid-diastolic to peak early diastolic velocity ratio were significantly lower in group 1 than in group 2 (91 +/- 31 vs 214 +/- 57 ms [p < 0.001], 0.35 +/- 0.08 vs 0.59 +/- 0.13 [p < 0.001], respectively). The best diagnostic accuracy (95%) was obtained with cut-off values of PHTPR < or = 150 ms and the lowest mid-diastolic to peak early diastolic velocity ratio < or = 0.5: sensitivity 100%, specificity 89%, positive predictive value 94%, and negative predictive value 100%. Using multiple logistic regression analysis, we found that PHTPR was the strongest predictor of RV involvement. Thus, these parameters, derived from pulmonary regurgitant tracings, are useful in the noninvasive bedside diagnosis of RV infarction.

Frequency of chronic obstructive airways disease and pulmonary hypertension in patients with acute inferior myocardial infarction with or without right ventricular infarction

OBJECTIVE

Factors influencing the incidence of right ventricular infarction among patients with acute inferior myocardial infarction have not yet been fully established. Chronic obstructive airways disease and right ventricular hypertrophy were suggested as possible predisposing factors but no definite evidence was shown. This study analyses the frequency of chronic obstructive airway disease and of Doppler assessed pulmonary hypertension among patients with acute inferior myocardial infarction with or without right ventricular infarction.

DESIGN AND PATIENTS

Sixty consecutive patients with acute inferior myocardial infarction were prospectively enrolled into the study.

MEASUREMENTS

Standard 12-lead ECG with right precordial leads (V3-6R) were recorded on admission to the Coronary Care Unit and on days 2 and 3. Doppler echocardiography was performed within 48 h after the onset of myocardial infarction and repeated 6 weeks later together with a pulmonary function test. Routine biochemical and clinical data were collected.

RESULTS

Right ventricular infarction occurred in 35% of patients with acute inferior myocardial infarction. No differences in respiratory indices of chronic obstructive airways disease or in Doppler echocardiography parameters of pulmonary hypertension were revealed among patients with and without right ventricular infarction. Peak total creatine kinase level and creatine kinase myocardial isoenzyme levels were higher in patients with right ventricular infarction than in those without (2925 +/- 1321 vs. 1682 +/- 1216 U/l; P < 0.001 and 207 +/- 108 vs. 127 +/- 102 U/l; P < 0.05, respectively).

CONCLUSIONS

In the course of acute inferior myocardial infarction, the frequencies of chronic obstructive airways disease and/or pulmonary hypertension were not higher among patients with right ventricular infarction than among those without right ventricular infarction. Thus, history of chronic obstructive airways disease and/or pulmonary hypertension do not necessitate specific precautions in respect of right ventricular infarction.

Right ventricular infarction

Right ventricular infarction complicates up to half of inferior left ventricular infarctions. The term represents a spectrum of disease from mild, asymptomatic right ventricular dysfunction to cardiogenic shock, and it includes transient ischemic myocardial dysfunction as well as myocardial necrosis. Right ventricular infarction is associated with considerable morbidity and mortality, and its presence defines a high-risk subgroup of patients with inferior left ventricular infarction. Diagnosis of this condition requires a high degree of suspicion based on clinical findings and the early recording of the electrocardiogram through right precordial leads, as well as elevated right-sided filling pressures out of proportion to left-sided filling pressures. The proper management of right ventricular infarction requires sustaining adequate right ventricular preload with volume loading and maintenance of atrioventricular synchrony, reduction of right ventricular afterload (particularly when left ventricular dysfunction is present), and inotropic support of the right ventricle. Early reperfusion with fibrinolytic therapy or direct angioplasty is also warranted. Survivors of right ventricular infarction generally have a restoration of normal right ventricular function with resolution of hemodynamic abnormalities.

Analysis of right ventricular kinesis by means of transesophageal echocardiography: present problems and perspectives

The evaluation of right ventricular (RV) kinesis by two-dimensional echocardiography represents a difficult task. Transthoracic echocardiography can visualize the RV in several projections, but the image quality and the variability of imaging views usually do not allow quantitative analysis. We investigated the potential of transesophageal echocardiography (TEE) for evaluating RV global function and regional kinesis, in 32 controls and in 16 patients with inferior myocardial infarction (MI) and asynergy involving the inferior wall of both ventricles. Good-quality images of at least one horizontal section of the RV were obtained in 73% of subjects by conventional, 90 degrees sector and in 100% of subjects by wide-angle, "panoramic" sector. Images of the RV in short-axis view at medium level were acquired and evaluated in 93% of cases, but at basal and apical levels only in 67% and 39%, respectively. The low percentage of successful detection and evaluation of the RV at apical level can be explained by prominent motion and trabeculation of the apex. Global systolic area changes (SAC) in controls attained similar values at apical and medium levels (60% and 59%, respectively), but were significantly lower (48%, P less than 0.05) at basal level. In patients with previous inferior MI and inferoposterior asynergy, global SAC were significantly (P less than 0.01) lower at medium and basal levels (32% and 27%, respectively) compared with controls. Regional kinesis of RV was assessed as segmental SAC in 12 different segments, by fixed and float system of center of cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Right ventricular dilatation and remodeling the first year after an initial transmural wall left ventricular myocardial infarction

Left ventricular (LV) remodeling after LV myocardial infarction was described previously. Little is known regarding concomitant adaptation, if any, in right ventricular (RV) volumes after LV infarction. To examine this issue, cine-computed tomography was used to determine serial changes in absolute global LV and RV volumes in 27 patients without clinical heart failure during the first year after an initial Q-wave myocardial infarction (14 anterior and 13 inferior). The patient group with anterior wall LV infarction showed progressive increases in LV and RV volumes from hospital discharge to 1 year (end-diastolic volumes +25 and +13%, respectively; and end-systolic volumes +35 and +15%, respectively). In patients with inferior wall LV infarction, both LV end-diastolic and end-systolic volumes increased significantly during the study period (+13 and +15%, respectively). Despite a trend for RV end-diastolic volume to be increased at 1 year, neither end-diastolic nor end-systolic volume increased significantly after hospital discharge following inferior wall LV infarction. Absolute RV end-diastolic volume was not significantly different between the infarct groups at any time after infarction. In conclusion, global changes occur in both LV and RV volumes during the first year after an initial infarction regardless of infarct location. The magnitude of these changes was greater after anterior than inferior wall LV infarction.

Diagnosis of right ventricular infarction by overlap images of simultaneous dual emission computed tomography using technetium-99m pyrophosphate and thallium-201

The validity of dual energy single-photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PPi) and thallium-201 for the diagnosis of right ventricular (RV) infarction, and the clinical features of RV infarction, were investigated in 190 patients with acute myocardial infarction. Diagnosis of RV infarction was performed by Tc-99m PPi accumulation in the RV myocardium on thallium-201 and Tc-99m PPi over-lay images at the dual SPECT with simultaneous imaging taken 2 to 9 days after the onset of myocardial infarction. Thirty RV infarctions were found among the 190 patients with left ventricular infarction (15.8%): 29 (97%) in association with the inferior and 1 (3%) with the lateral infarction. Tc-99m PPi accumulation was mostly observed in the posterior wall of the right ventricle. A total occlusion or a severe stenosis of the right coronary artery was demonstrated angiographically in 92% of the patients with RV infarction. The prevalence of RV infarctions was significantly lower in patients who achieved successful early reperfusion than in those who did not (26.7 vs 68.4%, respectively, p < 0.01). However, a successful early reperfusion therapy could not significantly decrease the rate of RV involvement in patients without significant collateral flow (p < 0.01). Thus, dual isotope SPECT with Tc-99m PPi and thallium-201 can be used as a reliable method for the diagnosis of RV infarction.

Effects of tissue plasminogen activator therapy on the frequency of acute right ventricular myocardial infarction associated with acute left ventricular infarction

To assess the effects of reperfusion therapy on acute right ventricular myocardial infarction, we studied at necropsy the hearts from 51 patients who died after receiving intravenous recombinant tissue plasminogen activator for acute left ventricular myocardial infarction as part of the Thrombolysis in Myocardial Infarction (TIMI) study. Right ventricular infarction occurred in none of 29 patients with infarction of the anterior wall of the left ventricle and in 8 of 22 patients (36%) with infarction of the posterior (inferior) wall of the left ventricle. Of the 22 patients with posterior wall infarction, the 8 patients with right ventricular infarction were compared to the 14 patients without right ventricular infarction. The patients with right ventricular infarction had a longer mean interval from tissue plasminogen activator infusion to peak creatine phosphokinase level (19 vs. 11 h, P < 0.03), a lower frequency of hemorrhagic necrosis (2 of 8 vs. 10 of 14, P < 0.04) and higher frequency of luminal thrombus in the infarct-related coronary artery (6 of 8 vs. 3 of 14, P = 0.054). Each of these findings is associated with the absence of coronary reperfusion. Thus, successful reperfusion following acute left ventricular myocardial infarction appears to be associated with a decreased frequency of concomitant right ventricular myocardial infarction.