Right ventricular infarction: relationships between ST segment elevation in V4R and hemodynamic, scintigraphic, and echocardiographic findings in patients with acute inferior myocardial infarction

The relationship between ST segment elevation on the right precordial lead V4R and the hemodynamic, echocardiographic, and myocardial scintigrapic signs suggestive of right ventricular (RV) infarction was studied in 42 patients with acute inferior myocardial infarction. Twenty-two patients had ST segment elevation in V4R. Among these patients, a significant correlation was demonstrated between V4R ST segment elevation and the hemodynamic (p less than 0.001), scintigraphic (p less than 0.001), and echographic (p less than 0.02) criteria for acute RV infarction. These results support the validity of this new electrocardiographic sign as a practical means in aiding the clinical detection of RV involvement with acute transmural inferior myocardial infarction.     

Right ventricular infarction/ischemia with precordial ST elevation: comparison with left ventricular anterior wall infarction]

Acute right ventricular (RV) infarction is sometimes accompanied by precordial ST elevation which is also suggestive of left ventricular (LV) anterior wall infarction. We compared 12-lead electrocardiograms between 2 groups of patients with initial acute myocardial infarction presenting precordial ST elevation, one with RV infarction (n = 11) and the other with LV anterior wall infarction (n = 42). The magnitude and extent of the ST elevation and the positions presenting the maximal ST elevation in the precordial leads differed between the 2 groups. In the inferior and lateral leads, the analysis of the ST segment shift aided in distinguishing between the 2 groups. The specific patterns of intraventricular conduction delay and frontal QRS-axis deviation were also useful for the differentiation. The best electrocardiographic variable for identifying RV infarction was inferior lead ST elevation, followed by maximal precordial ST elevation in lead V1, ST elevation limited to only one precordial lead and a cove-shaped pattern of RV conduction delay. The best electrocardiographic predictor for diagnosing LV anterior wall infarction was an isoelectric or depressed ST-segment in the inferior leads, followed by precordial ST elevation equal to or greater than 5 mm, maximal ST elevation in lead V3 or V4 and ST elevation in the lateral leads. We concluded that systematic analysis of the 12-lead electrocardiograms recorded in the hyperacute stage is valuable for distinguishing between acute RV infarction and LV anterior wall infarction.     

急性下壁心肌梗死伴胸导联ST段压低的临床意义

目的探讨急性下壁心肌梗死伴胸导联ST段压低的临床意义。方法观察64例急性下壁心肌梗死胸导联ST段压低与常规及24h动态心电图检查结果的关系。结果①单纯下壁心肌梗死不伴胸导联ST段改变显著多于伴胸导联ST段改变(P<0.01),下壁伴正后壁心肌梗死伴胸导联ST段改变显著多于不伴胸导联ST段改变(P<0.01),而下壁伴右心室心肌梗死与胸导联ST段改变无明显区别(P>0.05)。②伴胸导联ST段改变者严重室性心律失常与房室传导阻滞的发生率均较不伴胸导联ST段改变者高(P<0.05)。结论急性下壁心肌梗死伴胸导联ST段压低表明心肌梗死广泛,严重室性心律失常和房室传导阻滞的发生率明显增多。     

Right ventricular infarction: diagnostic value of ST elevation in lead III exceeding that of lead II during inferior/posterior infarction and comparison with right-chest leads V3R to V7R

The diagnostic accuracy of ST elevation in lead III exceeding that of lead II (ratio III/II greater than 1) in the diagnosis of right ventricular infarction was investigated in 24 autopsied patients with inferior/posterior myocardial infarction on ECG. The results were compared with the diagnostic accuracy of ST elevation greater than or equal to 1 mm in right-chest leads V3R to V7R recorded in the same patients. All had left ventricular infarction documented at autopsy, and 17 (71%) had concomitant right ventricular involvement. The highest specificity (100%) and positive predictive value (100%) were calculated for the right-chest leads, whereas values for ratio III/II greater than 1 were 88% and 91%, respectively. The differences were not statistically significant. It is concluded that differences in ST elevation in leads III and II can be the basis for a diagnosis of right ventricular involvement in ECG-diagnosed inferior/posterior infarction. The diagnosis, however, may be achieved more easily with right-chest leads.     

Implications of the absence of ST-segment elevation in lead V4R in patients who have inferior wall acute myocardial infarction with right ventricular involvement

BACKGROUND: ST-segment elevation of > or = 1.0 mm in lead V4R has been shown to be a reliable marker of right ventricular involvement (RVI), a strong predictor of a poor outcome in patients with inferior acute myocardial infarction (IMI). However, patients with no ST-segment elevation in lead V4R despite the presence of RVI have received little attention. HYPOTHESIS: The study was undertaken to study the clinical features of patients with no ST-segment elevation in lead V4R despite the presence of RVI, which means false negative, as such patients have received little attention in the past. METHODS: We studied 62 patients with a first IMI, who had total occlusion of the right coronary artery (RCA) proximal to the first right ventricular branch and successful reperfusion within 6 h from symptom onset, to examine the implications of the absence of ST-segment elevation in lead V4R despite the presence of RVI. RESULTS: A standard 12-lead electrocardiogram (ECG) and right precordial ECG (lead V4R) were recorded on admission, and three posterior chest ECGs (leads V7 to V9) were additionally recorded in 34 patients. Patients were classified according to the absence (Group 1, n = 18) or presence (Group 2, n = 44) of ST-segment elevation of > or = 1.0 mm in lead V4R on admission. Patients in Group 1 had a greater ST-segment elevation in leads V7 to V9 (2.9+/-2.4 vs. 1.4+/-3.0 mm. p < 0.05), a higher frequency of a dominant RCA (defined as the distribution score > or = 0.7) (72 vs. 11%, p < 0.001), and a higher peak creatine kinase level (3760+/-1548 vs. 2809+/-1824 mU/ml, p < 0.05) than those in Group 2. CONCLUSIONS: In patients with IMI caused by the occlusion of the RCA proximal to the first right ventricular branch, no ST-segment elevation in lead V4R can occur because of concomitant posterior involvement. In such patients, the incidence of RVI may be underestimated on the basis of ST-segment elevation in lead V4R.     

Right ventricular ejection fraction in patients with acute anterior and inferior myocardial infarction assessed by radionuclide angiography

We measured right and left ventricular ejection fracttion (EF) from high frequency time-activity curves obtained during the initial passage of an intravenous bolus of 99mTc (Sn) pyrophosphate. In 22 normal controls right ventricular EF averaged 0.52 +/- 0.04 (SD). In 24 acute anterior or lateral infarction patients right ventricular EF was normal (0.56 +/- 0.10), while left ventricular EF was reduced (0.45 +/- 0.10, P less than 0.001 vs controls). In 19 acute inferior infarction patients left ventricular EF also was depressed (0.51 +/- 0.09, P less than 0.001 vs controls). Among 7 of 19 inferior infarction patients with right ventricular by scintigraphy, right ventricular EF was reduced (0.39 +/- 0.05; P less than 0.001 vs normals; P less than 0.01 vs inferior infarction patients without right ventricular involvement). In the latter group right ventricular EF averaged 0.51 +/- 0.10 (NS vs normals). We conclude 1) a single injection of 99mTc (Sn) pyrophosphate can identify right and left ventricular dysfunction and infarct location in acute myocardial infarction, 2) right ventricular EF is well-preserved except when inferior infarction involves the right ventricle.     

aVR导联ST段抬高对急性心肌梗死预后的价值

目的探讨心电图aVR导联ST段抬高对急性前壁心肌梗死患者预后的价值。方法首次入院急性前壁心肌梗死患者57例，对其心电图和冠状动脉造影及临床资料进行对比分析。根据心电图aVR导联ST段变化分为抬高组、无偏移组。结果梗死相关血管为左主干病变的ST段抬高组、ST段无偏移组分别为5例（21．7％）、1例（2．9％），两组统计有显著性差异（p〈0．01）；病变范围为多支病变ST段抬高组、ST段无偏移组分别为10例（43．4％）、8例（23．5％），两组统计有显著性差异（p〈0．05）；发生心脏事件ST段抬高组、ST段无偏移组分别为8例（34.8％）、3例（8．8％），两组有显著性差异（p〈0．01）。结论aVR导联ST段抬高对预测急性前壁心肌梗死患者的预后有重要的价值，应高度重视。     

年龄对急性ST段抬高型心肌梗死患者左室射血分数的影响

目的:分析年龄对急性ST段抬高型心肌梗死患者(STEMI)左室射血分数(LVEF)的影响.方法:收集急性STEMI患者245例,根据年龄分为5组:≤50岁组(49例)、51～60岁组(70例)、61～70岁组(62例)、71～ 79岁组(50例)、≥80岁组(14例);对临床基线资料(包括年龄、性别、高血压、糖尿病、高血脂、吸烟史、超急性期及急性期ST段抬高导联数、入院时及入院12～72 h肌钙蛋白、Killip分级、LVEF、是否接受冠状动脉介入治疗(PCI)和住院期间死亡等)进行比较分析.结果:多元线性回归分析显示,LVEF与年龄(P＜0 05)和肌钙蛋白(P＜0.05)呈负相关,随着年龄增长,LVEF降低;随着肌钙蛋白的增加,LVEF降低.在≤50岁组LVEF显著高于其余各年龄组(均P＜ 0.05),而≥80岁组LVEF则显著低于其余各组(均P＜0.05).≥80岁组KilliP分级≥Ⅱ级者显著高于其余各组(均P＜0.05).≥80岁组患者的住院期间病死率显著高于≤50岁组、51～60岁组、61～ 70岁组(均P＜0.05).结论:年龄可作为影响急性STEMI患者心功能的独立危险因素.     

Value of ST elevation in lead III greater than lead II in inferior wall acute myocardial infarction for predicting in-hospital mortality and diagnosing right ventricular infarction

ST elevation in lead III > II has a higher sensitivity than lead V4R in diagnosing right ventricular myocardial infarction. Lead III > II is also predictive of in-hospital mortality.     

急性下壁心肌梗死心电图胸前导联V1-3 ST段抬高的临床意义

目的 探讨急性下壁心肌梗死患者心电图胸前导联ST段抬高与冠状动脉造影所示冠状动脉病变的关系及其临床意义.方法 187例急性下壁心肌梗死患者,按入院时18导心电图胸前导联ST段改变分为2组,ST段抬高组（16例）和非ST段压低组（171例）.所有患者均行冠状动脉造影术,病变适合行经皮腔冠状动脉成型术并检测B型钠尿肽（BNP）.结果 急性下壁心肌梗死伴胸前导联ST段抬高时多为右冠状动脉近段闭塞,尤其是圆锥支闭塞（P＜0.01）,且伴有右心功能不全和血流动力学障碍,与下壁右室心梗相比BNP差异有统计学意义（P＜0.01）.结论 急性下壁心肌梗死合并胸前导联ST抬高表明为右冠状动脉近段或开口闭塞且多伴右室心肌梗死和心功能不全.     

Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1).

OBJECTIVES: We sought to determine the electrocardiographic (ECG) features associated with acute left main coronary artery (LMCA) obstruction. BACKGROUND: Prediction of LMCA obstruction is important with regard to selecting the appropriate treatment strategy, because acute LMCA obstruction usually causes severe hemodynamic deterioration, resulting in a less favorable prognosis. METHODS: We studied the admission 12-lead ECGs in 16 consecutive patients with acute LMCA obstruction (LMCA group), 46 patients with acute left anterior descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group). RESULTS: Lead aVR ST segment elevation (>0.05 mV) occurred with a significantly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was significantly higher in the LMCA group (0.16 +/- 0.13 mV) than in the LAD group (0.04 +/- 0.10 mV). Lead V(1) ST segment elevation was lower in the LMCA group (0.00 +/- 0.21 mV) than in the LAD group (0.14 +/- 0.11 mV). The finding of lead aVR ST segment elevation greater than or equal to lead V(1) ST segment elevation distinguished the LMCA group from the LAD group, with 81% sensitivity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and the inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher ST segment elevation in lead aVR than in those with less severe elevation. CONCLUSIONS: Lead aVR ST segment elevation with less ST segment elevation in lead V(1) is an important predictor of acute LMCA obstruction. In acute LMCA obstruction, lead aVR ST segment elevation also contributes to predicting a patient's clinical outcome.     

Early diagnosis of right ventricular or posterior infarction associated with inferior wall left ventricular acute myocardial infarction

Right ventricular (RV) or posterior infarction associated with inferior wall left ventricular acute myocardial infarction (AMI) has important therapeutic and prognostic implications. However, RV and posterior chest leads in addition to the 12-lead electrocardiogram are required for accurate detection. Body surface mapping (BSM) has greater spatial sampling and may further improve inferior wall AMI classification. Consecutive patients with chest pain lasting <12 hours were assessed to identify those with AMI and > or =0.1 mV ST elevation in > or =2 contiguous inferior leads of the 12-lead electrocardiogram (bundle branch block or left ventricular hypertrophy excluded). A 12-lead electrocardiogram, RV leads (V(2)R, V(4)R), posterior chest leads (V(7), V(9)), and a BSM were recorded. From each BSM, the 12 electrodes overlying the RV region (regional RV map) and 10 electrodes overlying the posterior wall (regional posterior map) were assessed for ST elevation. Infarct size was estimated by serial cardiac enzymes. AMI occurred in 173 of 479 patients. Of the 62 patients with inferior wall AMI, ST elevation > or =0.1 mV occurred in 26 patients (42 in V(2)R or V(4)R compared with 36 patients (58%) in > or =1 electrode on the regional RV map (p = 0.0019). ST elevation > or =0.1 mV occurred in 1 patient (2%) in V(7) or V(9) compared with 17 patients (27%) in > or =1 electrode on the regional posterior map (p = 0.00003). ST elevation > or =0.05 mV occurred in 6 patients (10%) in V(7) or V(9) compared with 22 patients (36%) in > or =1 electrode on the regional posterior map (p = 0.00003). Patients with ST elevation on regional RV and/or posterior maps had a trend toward larger infarct size (mean peak creatine kinase 1,789+/-226 vs. 1,546+/-392 mmol/L; p = NS). Thus, BSM, when compared with RV or posterior chest leads, provides improved classification of patients with inferior wall AMI and RV or posterior wall involvement.     

Stress-induced ST segment shift in leads V3R and V4R after acute myocardial infarction.

A total of 107 patients with acute myocardial infarction underwent a dobutamine stress test and received increasing doses of the drug (5, 10, 15, 20, and up to 40 micrograms/kg/min). Coronary angiography was performed within the first month. The 12 conventional ECG leads plus the right chest leads V3R and V4R were recorded under basal conditions and after each dose of dobutamine. In 51 patients (group A) there was an ST shift greater than or equal to 0.5 mm in the right chest leads, with two different patterns: rightward (V2 less than V1 less than V3R V less than V4R) (n = 26) and leftward (V2 less than V1 less than V3R greater than V4R) (n = 25). In 56 patients (group B) no ST shift in the right chest leads was induced. An ST segment elevation greater than or equal to 0.5 mm in V4R was 43% sensitive and 86% specific for the detection of proximal right coronary artery disease. Four subgroups were established in group A: A1R, rightward ST elevation (n = 23); A1L, leftward ST elevation (n = 12); A2R, rightward ST depression (n = 3); and A2L, leftward ST depression (n = 13). Group A1R had predominantly inferior infarcts and right coronary artery stenoses, group A1L had predominantly anterior infarcts and left anterior descending coronary stenoses, and group A2L had posteroinferior infarcts and right or left circumflex stenoses, all of them with low sensitivity (less than 50%) and high specificity (greater than 87%) for a such diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

ST-segment re-elevation unrelated to left ventricular ejection fraction or volume after anterior wall acute myocardial infarction treated with successful reperfusion

Ventricular remodeling is a major determinant of the long-term prognosis of patients with acute myocardial infarction (AMI). No previous study examined the relation of ST-segment re-elevation to left ventricular (LV) volume and function in patients with successful reperfusion. We examined the relation of ST-segment re-elevation to LV function and volume indices in 51 patients with anterior wall AMI who underwent successful reperfusion by direct coronary angioplasty. A 12-lead electrocardiogram was recorded once a day until 7 days after the onset of AMI. ST-segment shift was measured and Sigma ST was defined as the sum of ST-segment elevation obtained from leads V2, V3, and V4. ST-segment re-elevation was defined as present when the difference between maximal and minimal Sigma ST (Delta ST) was >0.3mV. LV indices were obtained from left ventriculography performed approximately 1 month after the onset of AMI. ST-segment re-elevation was observed in 15 patients (29%). No significant differences were observed between the ST- re-elevation group and non-ST-re-elevation group in LV ejection fraction (49.4+/-14.0 vs. 51.2+/-11.5%), LV end-systolic volume index (35.8+/-13.1 vs. 33.8+/-12.5 mL/m(2)) or LV end-diastolic volume index (69.7+/-12.8 vs. 68.3+/-14.4 mL/m(2)). The difference between maximal and minimal Sigma ST (Delta ST) was not significantly correlated with any LV index examined. In conclusion, the present study revealed that ST-segment re-elevation after successful reperfusion in anterior wall AMI patients was not related to LV volume or function, indicating that ST-re-elevation is not a clinically meaningful indicator of LV remodeling.     

Clinical significance of ST-segment elevation in lead V1 in patients with acute inferior wall Q-wave myocardial infarction

BACKGROUND: This study was designed to determine the clinical significance of ST-segment elevation in the precordial leads (leads V1 and V2) in acute Q-wave inferior wall myocardial infarction. METHODS AND RESULTS: One hundred fifty-eight consecutive patients with acute Q-wave inferior wall myocardial infarction were classified into 3 groups on the basis of the initial ST-change in V1 (group 1 = 29 patients with ST elevation, group 2 = 97 patients with ST depression, and group 3 = 32 patients with no ST-segment change). The right coronary artery was the infarct-related artery in all the patients in group 1. Although there was no significant difference between groups 1 and 2, the number of left ventricular asynergic segments was larger and the incidence of major in-hospital arrhythmias was higher in groups 1 and 2 compared with group 3. Patients in group 1 had a significantly higher incidence of proximal lesion (86%) and right ventricular infarction (69%) than the other 2 groups did. When ST elevation in leads V1 and V2 was considered, 14 of 15 patients (93%) with ST elevation only in V1 had right ventricular infarction, whereas 6 of 14 patients (43%) with ST elevation in both V1 and V2 had right ventricular infarction (P =.011). CONCLUSIONS: ST-segment elevation in V1 on admission in patients with acute Q-wave inferior wall myocardial infarction indicates a right coronary artery lesion associated with a larger infarct size and a higher incidence of major in-hospital arrhythmias.     

Influence on prognosis and morbidity of left ventricular ejection fraction with and without signs of left ventricular failure after acute myocardial infarction

The left ventricular (LV) ejection fraction (EF) is known to be an independent predictor of late prognosis after acute myocardial infarction. Despite a previous report that early heart failure (evidenced only by advanced pulmonary rales in the hospital) can predict prognosis in the absence of severe depression of the LVEF at hospital discharge, the potentially strong influence of various measures of in-hospital heart failure on the predictive ability of LVEF has not been generally appreciated. Accordingly, in 972 patients with acute myocardial infarction the effect on late mortality of the presence or absence in-hospital of both clinical and radiographic signs of LV failure in subgroups of patients with normal, moderately or severely depressed LVEF was examined and measured close to hospital discharge. Patients were divided into 3 groups according to LVEF: group I LVEF less than or equal to 40, n = 265; group II LVEF 0.41 to 0.50, n = 241 and group III LVEF greater than or equal to 0.51, n = 466. When clinical signs of LV failure were present at any time during the coronary care unit period, the 1-year mortality rate after hospital discharge in groups I, II and III was 26, 19 and 8%, compared with 12% (p less than 0.01), 6% (p less than 0.01) and 3% (p less than 0.02), respectively, when signs of LV failure were absent.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical characteristics of ST-segment elevation in lead V6 in patients with Q-wave acute inferior wall myocardial infarction

BACKGROUND: Precordial ST-segment depression in acute inferior infarction is well recognized, but few studies have evaluated ST-segment elevation in lateral precordial leads. The present study examined the clinical significance of ST-segment elevation in lead V6 in patients with acute Q-wave inferior myocardial infarction. METHODS: We studied the initial electrocardiography of 125 consecutive patients with acute Q-wave inferior myocardial infarction admitted to hospital within 12 h of the onset of chest pain. They were classified into two groups: group 1 = 34 patients with ST-segment elevation in lead V6; group 2 = 91 patients with no ST-segment elevation in lead V6. RESULTS: Among the seven clinical variables examined, the number of left ventricular asynergic segments (P < 0.001) and pulmonary capillary wedge pressure (P = 0.001) were related to ST-segment elevation in lead V6. The incidences of major arrhythmias (50% compared with 31%, P = 0.04), pericardial effusion (32% compared with 9%, P = 0.003), and pericardial rub (15% compared with 2%, P = 0.02) during the patients' stay in hospital were greater in group 1 than in group 2. Among the patients in group 1, the right coronary artery was the culprit artery in 22 of 24 patients (92%) with ST segment depression in lead I, whereas the circumflex artery was the culprit artery in nine of 10 patients (90%) with isoelectric or ST-segment elevation in lead I. CONCLUSION: The presence of ST-segment elevation in lead V6 in patients with acute Q-wave inferior myocardial infarction was associated with larger infarct size, and greater incidences of major arrhythmias and pericardial involvement during the patient's stay in hospital.