Value of electrocardiogram in diagnosing right ventricular involvement in patients with an acute inferior wall myocardial infarction

To study the value of the electrocardiogram in diagnosing right ventricular involvement in acute inferior wall myocardial infarction, the electrocardiographic findings were analysed in 67 patients who had had scintigraphy to pin-point the infarct. All 67 patients were consecutively admitted because of an acute inferior wall infarction. A 12 lead electrocardiogram with four additional right precordial leads (V3R, V4R, V5R, and V6R) was routinely recorded on admission and every eight hours thereafter for three consecutive days. Thirty-six to 72 hours after the onset of chest pain a 99mtechnetium pyrophosphate scintigraphy and a dynamic flow study were performed to detect right ventricular involvement, which was found in 29 of the 67 patients (43%). ST segment elevation greater than or equal to 1 mm in leads V3R, V4R, V5R, and V6R is a reliable sign of right ventricular involvement. ST segment elevation greater than or equal to 1 mm in lead V4R was found to have the greatest sensitivity (93%) and predictive accuracy (93%). The diagnostic value of a QS pattern in lead V3R and V4R or ST elevation greater than or equal to 1 mm in lead V1 was much lower. ST segment elevation in the right precordial leads was short lived, having disappeared within 10 hours after the onset of chest pain in half of our patients with right ventricular involvement. When electrocardiograms are recorded in patients with an acute inferior wall infarction within 10 hours after the onset of chest pain, additional right ventricular infarction can easily be diagnosed by recording lead V4R.     

Right and left ventricular ejection fraction in acute inferior wall infarction with or without ST segment elevation in lead V4R

To detect right ventricular involvement, lead V4R was recorded within 10 hours of the onset of chest pain in 42 consecutive patients admitted with acute inferior wall myocardial infarction. One week after the acute infarction, multigated equilibrium radionuclide ventriculography was performed to assess right and left ventricular ejection fraction. Two weeks after the acute infarction, coronary angiography was performed to determine the site and location of the obstruction leading to the infarction. Seventeen patients had an obstruction in the right coronary artery proximal to the first branch to the right ventricular free wall (group 1); all of these had ST segment elevation in lead V4R. Fourteen patients had an obstruction in the right coronary artery distal to the first branch to the right ventricular free wall (group 2); only two of these patients had ST segment elevation in lead V4R. In 11 patients, the obstruction was located in the circumflex coronary artery (group 3); none of these had ST segment elevation in lead V4R. Nineteen patients had ST segment elevation of 1 mm or greater in lead V4R (group 4). Left ventricular ejection fraction was not different among the four groups of patients, although the right ventricular ejection fraction was significantly lower in group 1 and group 4 patients. It is concluded that ST segment elevation in lead V4R reliably identifies the group of patients with inferior wall myocardial infarction with depressed right ventricular function. This phenomenon persists for at least 1 week after infarction.     

Right ventricular infarction caused by isolated right ventricular branch occlusion: a case report

It is rare to observe right ventricular infarction caused by isolated right ventricular branch occlusion. Isolated right ventricular infarction accounts for less than three percent of all cases of infarction. Generally, it is associated with occlusion of a non dominant right coronary artery or of a right ventricular branch. ECG can be misleading with ST segment elevation in anterior leads. We describe a patient admitted for chest pain with ST segment elevation in leads V1 to V3 associated with ST segment elevation in leads V3R and V4R. Coronary angiography demonstrated isolated total occlusion of the right ventricular branch. Thus, right precordial leads need to be done in every patient presenting with ST segment elevation in precordial leads V1 to V3 and not only in inferior myocardial infarction.     

Comparison of diagnostic accuracy, time dependency, and prognostic impact of abnormal Q waves, combined electrocardiographic criteria, and ST segment abnormalities in right ventricular infarction.

OBJECTIVE--To determine the diagnostic and prognostic impact of abnormal Q waves in comparison to or in combination with ST segment abnormalities in the right precordial and inferior leads as indicators of right ventricular infarction during the acute phase of inferior myocardial infarction. DESIGN--Prospective study of a consecutive series of 200 patients with acute inferior myocardial infarction with and without right ventricular infarction. SETTING--Department of internal medicine, university clinic. RESULTS--Right ventricular infarction was diagnosed in 106 (57%) out of 187 patients from the results of coronary angiography, technetium pyrophosphate scanning, and measurement of haemodynamic variables or at necropsy, or both. In the acute phase of inferior infarction ST segment elevation > or = 0.1 mV in any of the right precordial leads V4-6R was the most reliable criterion for right ventricular infarction (sensitivity, 89%; specificity, 83%). Abnormal Q waves in the right precordial leads, the most specific criterion (91%) for right ventricular infarction, were superior to ST segment elevation in patients admitted > 12 hours after the onset of symptoms. Both ST segment elevation in leads V4-6R (increase in in hospital mortality, 6.2-times; P < 0.001; major complications, 2.3-times; P < 0.01) and abnormal Q waves (2.3-times, P < 0.05; 1.8-times, P < 0.05) on admission were highly predictive of a worse outcome during the in hospital period. In the presence of inferior myocardial infarction previously proposed combined electrocardiographic criteria were not better diagnostically or prognostically than ST segment abnormalities and abnormal Q waves alone. CONCLUSIONS--During the first 24 hours of inferior myocardial infarction ST segment elevation and abnormal Q waves derived from the right precordial leads are complementary rather than competitive criteria for reliably diagnosing right ventricular infarction, both indicating a worse in hospital course for the patient. In this they are better than any other previously proposed combined electrocardiographic criteria in diagnosing right ventricular infarction. Right precordial leads should be routinely monitored in acute 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.     

急性下壁心肌梗死患者心电图胸前导联ST段改变的临床意义

目的探讨急性下壁心肌梗死患者心电图胸前导联ST段改变与冠状动脉造影(CAG)所见冠状动脉病变部位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3组,ST段无变化组(47例),ST段抬高组(16例),ST段压低组(124例);所有患者均行CAG。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(RCA)近段闭塞(14例,82.3%),尤其是伴圆锥支动脉闭塞,与RCA中远端闭塞(2例,5.9%)比较差异有统计学意义(P0.01),且14例(73.7%)伴有右心功能不全和血流动力学障碍。下壁心肌梗死胸前导联ST段压低者可见于RCA、回旋支(LCX)闭塞及RCA、LCX闭塞与前降支(LAD)、对角支(D)病变的不同组合,其中LCX闭塞伴RCA病变者多表现为朐前ST V_4～V_6的压低,RCA闭塞伴LAD近端病变多有胸前ST V_1～V_6的压低,RCA伴D病变胸前ST V_1～V_3压低,与对照组比较差异有统计学意义(P0.05)。结论急性下壁心肌梗死合并胸前导联ST段抬高表明为RCA近段或丌口闭塞且多伴右心室心肌梗死和心功能不全;下壁心肌梗死伴胸前导联ST段压低提示为多支病变,ST V_1～V_3压低多伴有对角支严重狭窄,STV_1～V_6压低多伴有前降支的严重狭窄。     

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.     

头胸导联右胸心电图诊断急性右室梗塞的价值

选择急性下壁合并右室梗塞（依据血液动力学诊断）患者３４例，比较其同部位、同时间右胸Ｗｉｌｓｏｎ导联（Ｖ３Ｒ～Ｖ７Ｒ）和头胸导联（ＨＶ３Ｒ～ＨＶ７Ｒ）的心电图，探讨后者诊断急性右室梗塞的价值。首次记录心电图的时间为发病１０（平均４±２．８）ｈ２４例（Ａ组），超过１０（平均３１±１６．８）ｈ１０例（Ｂ组），两组Ｖ５Ｒ～Ｖ７Ｒ、ＨＶ５Ｒ～ＨＶ７Ｒ导联病理性Ｑ波出现率均为１００％。Ｖ４Ｒ（ＨＶ４Ｒ）或Ｖ７Ｒ（ＨＶ７Ｒ）ＳＴ段抬高≥０．１ｍＶ者，Ａ组为１００％，Ｂ组Ｗｉｌｓｏｎ导联为６０％、头胸导联为１００％。头胸导联ＳＴ段抬高幅度高于Ｗｉｌｓｏｎ导联０．０５～０．１５ｍＶ；头胸导联不仅ＱＲＳ－Ｔ波群呈现急性损伤期向充分发展期的衍变与ａＶＦ导联一致，并且ＳＴ段抬高持续的时间也与ａＶＦ导联一致，此特征有利于急性右室梗塞的诊断。     

Electrocardiographic criteria for the diagnosis of right ventricular involvement in the setting of acute inferior infarction.

Surface electrocardiograph of twelve cases of isolated left ventricular inferior infarction and 24 cases of biventricular inferior infarction confirmed by two-dimensional echocardiography were analysed. ST segment elevation in lead III more than in lead II and ST segment depression in leads I and aVL were highly sensitive in diagnosing right ventricular involvement. ST segment depression in lead V3 equal to or greater than ST segment elevation in lead III was highly specific but had low sensitivity. These findings can be helpful in cases where right sided chest leads have not been recorded or are inconclusive.     

ST segment elevation in anterior precordial leads and right ventricular infarction. Apropos of 6 cases]

ST segment elevation in the anterior precordial chest leads may be observed in some cases of right ventricular infarction alone or associated with left ventricular inferior wall infarction. Six out of 700 patients admitted to our Coronary Care Unit over a 2 year period had right ventricular infarction with these electrocardiographic changes. In three cases, isolated right ventricular infarction was due to occlusion of a right marginal artery (N = 2) or of a small right coronary artery (N = 1) which only vascularised the right ventricle. In 2 cases, right ventricular infarction was associated with a recent or chronic left ventricular inferior wall infarct. This type of ST segment elevation may suggest a left ventricular anterior wall infarct especially when there are no changes in the inferior leads, as was the case in our first patient. However, the dome-like appearance of the ST segment, the reduction in amplitude of ST elevation from V2 to V5, the progressive regression of the ST changes without the appearance of Q waves, are more suggestive of the diagnosis of right ventricular infarction. In addition, normal left ventricular dilatation on echocardiographic examination rapidly confirms the diagnosis.     

Value of lead V4R for recognition of the infarct coronary artery in acute inferior myocardial infarction

In 84 patients with an acute inferior wall myocardial infarction (MI) admitted within 10 hours after the onset of chest pain, a right precordial lead V4R electrocardiogram was recorded in addition to the standard 12-lead electrocardiogram. The presence or absence of ST-segment elevation in lead V4R was correlated with results of coronary angiography performed 2 to 26 weeks (mean 10) after MI. Patients were classified into 3 groups: (1) those with a critical stenosis or occlusion proximal to the first right ventricular (RV) branch (27 patients); (2) those with stenosis distal to the right ventricular branch of the right coronary artery (36 patients); and (3) those with stenosis in the left circumflex coronary artery (21 patients). The presence of ST-segment elevation greater than or equal to 1 mm in lead V4R has a sensitivity of 100% and a specificity of 87% for occlusion of the right coronary artery above the first RV branch; the predictive accuracy is 92%. Seven of 36 patients with a distal occlusion of the right coronary artery showed ST-segment elevation of 1 mm or more in lead V4R . The absence of ST-segment elevation greater than or equal to 1 mm in lead V4R excluded proximal occlusion of the right coronary artery. ST-segment elevation in lead V4R was not seen either in 29 of 36 patients with a distal occlusion of the right coronary artery or in all patients with an occlusion of the left circumflex artery. Recording of lead V4R within 10 hours after onset of acute inferior wall MI can give information rapidly about the vessel responsible for MI.(ABSTRACT TRUNCATED AT 250 WORDS)     

Right precordial ST and QRS changes in the diagnosis of right ventricular infarction

Two groups of patients with anatomically proved acute myocardial infarction were compared in order to study specificity and sensitivity of the ECG criteria previously described in clinical and experimental right ventricular infarction ( RVI ). Group 1 included 21 patients with left inferior infarction and with a variable degree of right ventricular involvement; group 2 included nine patients with myocardial infarction confined to the left inferior wall. In both groups the presence of ST elevation (at least 0.05 mV) and the morphology of the QRS complex in V4R , V3R, and V1 were assessed in ECGs performed at the time of admission. Also, in order to evaluate the morphology of the ST segment and QRS complex in right precordial leads in normal subjects, an ECG with 12 standard and four right precordial leads ( V6R to V3R) was performed in 82 subjects (group 3) without clinical and ECG evidence of heart disease. Our data reveal that in normal subjects an rS pattern is always present in V3R and frequently (91%) in V4R . On the contrary, the presence of QS or QR complexes in both V4R and V3R are specific markers of right ventricular necrosis (specificity 100%; sensitivity 78%). The presence of injury and necrosis waves in V4R or V4R to V3R during inferior infarction is a useful diagnostic criterion in that it insures a highly specific diagnosis of acute RVI in the great majority (76 and 71%, respectively) of the cases with autopsy evidence of right ventricular involvement.     

Electrocardiographic findings in acute right ventricular infarction: sensitivity and specificity of electrocardiographic alterations in right precordial leads V4R, V3R, V1, V2, and V3

To determine the sensitivity, specificity, predictive value and diagnostic efficiency of electrocardiographic alterations in the diagnosis of acute right ventricular infarction, 43 autopsy patients with acute myocardial infarction and an electrocardiogram including 12 leads plus leads V3R and V4R were studied. Group A included 21 patients with right ventricular infarction, of whom 14 (group AI) had posterior and 7 (group AII) had anterior right ventricular infarction. Group B included 22 patients without right ventricular infarction. Excluding group AII patients, the sensitivity of the presence of a Q wave reached 78.6% in lead V4R and decreased in leads V1 to V3; its specificity was low in all the leads. The sensitivity of ST segment elevation reached 100% in lead V4R and decreased in leads V1 to V3; its specificity was highest (68.2%) in leads V4R and V3R, its negative predictive value was 100% and its diagnostic efficiency was 80.6%. The criterion of ST segment elevation in lead V4R being higher than that in leads V1 to V3 was less sensitive (78.6%) than ST segment elevation in lead V4R alone, but its specificity reached 100%, its positive predictive value 100% and its diagnostic efficiency 91.7%. In conclusion, there are no electrocardiographic criteria to identify anterior right ventricular necrosis, but posterior right ventricular necrosis may be identified by the presence of a Q wave or ST segment elevation in the right precordial leads, reaching the highest sensitivity and specificity in lead V4R. The criterion of ST segment elevation in lead V4R being higher than that in leads V1 to V3 offers the highest specificity and efficiency in the diagnosis.     

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.     

Primary angioplasty for isolated right ventricular infarction.

We describe a case of isolated right ventricular infarction that has rarely been diagnosed antemortem. Electrocardiogram showed ST segment elevation in left precordial chest, right precordial chest, and inferior leads, which mimicked those of anterior and inferior left ventricular infarction. Coronary angiography revealed that culprit lesion was totally occluded right coronary artery. Infarcted artery was nondominant right coronary artery with branches supplying only right ventricular wall. Restoration of coronary blood flow was obtained by primary stenting and resulted in prompt ST segment normalization in all leads. Despite extensive right ventricular wall motion abnormality, subsequent right ventricular dysfunction was not observed.     

S-T segment depression in right-sided precordial leads during acute inferior wall infarction.

Right-sided chest leads (V3-V4R) were recorded in the early stages of first inferior wall acute myocardial infarction (AMI) in 100 consecutive patients. Nine patients (9%) presenting with S-T segment depression (greater than 1 mm) in these leads were subsequently studied by echocardiography and radionuclear angiography. In this group, there were 5 patients with intact right ventricular (RV) function and 4 other patients with clinical findings compatible with RV infarction. We suggest that one should not rule out RV involvement when S-T segment depression rather than elevation is seen in the right precordial leads in the presence of inferior wall AMI. An individual assessment for RV infarction is recommended when this pattern is apparent on the ECG.     

Marked ST-segment elevation in the precordial and inferior leads in right ventricular myocardial infarction: a case report

This is a report of right ventricular infarction complicated by inferior myocardial infarction in which marked ST-segment elevation was observed in the precordial and inferior leads. A 51-year-old man was admitted with chest pain of one-half hour duration. His admission ECG showed conspicuous ST-segment elevation in the precordial and inferior leads. The maximum magnitude of the ST-segment elevation in the precordial leads was 21 mm in lead V2 and 10 mm in lead II. Echocardiography showed akinesis of the right ventricular free wall and the posterior half of the left ventricle. Angiography revealed a 90% reduction in the diameter of the right coronary artery in its proximal portion, and a normal left coronary system. Recent reports have indicated that precordial ST-segment elevation may reflect right ventricular infarction. However, there has been no previous report of marked ST-segment elevation in the precordial and inferior leads. In right ventricular infarction, the currents of injury usually occur simultaneously in the right ventricular free wall and left ventricular inferior wall, and then are electrically opposed to each other. The diffuse and marked ST-segment elevation observed in this case is thus a rare phenomenon.     

Diagnostic Value of aVL Derivation for Right Ventricular Involvement in Patients with Acute Inferior Myocardial Infarction

Background: Right ventricular (RV) involvement is associated with increased morbidity and mortality in patients with acute inferior myocardial infarction (MI). Although electrocardiography is probably the most useful, simple, and objective tool for the diagnosis of acute MI, there are no well‐defined criteria in the standard 12‐lead electrocardiogram to properly identify RV involvement in patients with acute inferior MI. Our objective was to evaluate the value of ST‐segment depression in lead aVL in diagnosing RV involvement in patients with acute inferior MI. Materials and Methods: Sixty‐seven patients, hospitalized with acute inferior myocardial infarction, were included in this study. The diagnosis of acute inferior myocardial infarction was based on the clinical history, characteristic enzyme pattern of CK‐MB values, and the appearance of ST‐segment elevation ≥ 1 mm in at least two of the leads (leads II, III, aVF). RV infarction was defined by ST‐segment elevation ≥ 1mm in lead V4R. ST‐segment depression in lead aVL that is more than 1 mm was accepted as a diagnostic criterion for RV involvement in patients with acute inferior MI. Results: Thirty‐one patients had >1 mm ST‐segment depression and 28 of them had right ventricular infarction according to lead V4R. Thirthy‐six patients showed ≤1 mm ST‐segment depression indicating no right ventricular involvement but four of them also had right ventricular infarction according to V4R. Conclusion: More than 1 mm ST‐segment depression in lead aVL was found to have high sensitivity (87%), specificity (91%), high positive and negative predictive value (90%, 88%, respectively), and high diagnostic accuracy (89%) in diagnosing RV involvement in patients with acute inferior MI. Therefore, by using a simple 12‐lead electrocardiographic sign, ST‐segment depression >1 mm in lead aVL, obtained on admission, it is possible to identify RV involvement in patients with acute inferior MI.     

Correlation between the electrocardiogram and regional wall motion abnormalities as detected by echocardiography in first inferior acute myocardial infarction

We assessed the correlation between ST deviation in each of the six precordial leads and the presence of regional wall motion abnormalities (RWMA) as assessed by transthoracic echocardiography in 109 patients with first inferior acute myocardial infarction. ST depression in lead V1 and V2 was associated with higher incidence of RWMA of the mid-posterior segment (p < 0.02 for both leads). The specificity of ST segment depression in leads V1 and V2 for RWMA in mid-posterior segment was 87 and 57%, and the sensitivity 36 and 70%, respectively. Patients with ST depression in leads V2 or V3 had worse global RWMA score than patients without ST depression in these leads (p = 0.009 and p = 0.025, respectively). Patients with an ST elevation in lead V1, but not in leads V2 or V3, had a higher prevalence of right ventricular involvement (p < 0.0001). ST elevation in lead V5 was associated with more frequent involvement of the apical portion of the inferior wall (p < 0.02), with specificity of 88% and sensitivity of 33%. Global RWMA score was significantly worse for patients with ST elevation than for patients with isoelectric ST in lead V5 (p = 0.024). ST elevation in lead V6 was associated with RWMA in the mid-posterior segment (p < 0.006), with specificity of 91% and sensitivity of 33%, and worse global RWMA score (p = 0.022).     

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.