Electrocardiographic findings in accessory right precordial leads in adults and seniors with notched S waves in lead V1-a preliminary study.

BACKGROUND: Atypical right bundle branch block (RBBB) may present with an rS pattern and notched S wave in lead V1 . The notched S wave may represent slowed conduction or delayed activation of the right ventricular conduction system or ventricular myocardium. METHODS: We retrospectively analyzed the QRS patterns in accessory right precordial leads (from V3 R to V5 R) in 15 adults/senior individuals with notched S wave in lead V1 . RESULTS: In the right accessory precordial leads, 13 showed triphasic QRS pattern with final R' wave in their QRS complexes. This QRS pattern in association with notched S wave in lead V1 is suggestive of the presence of RBBB (incomplete or complete). CONCLUSIONS: A notched S wave in lead V1 and in the right precordial accessory leads associated with a final R' wave suggests the possibility of concealed RBBB (incomplete or complete).

Correlation between ST-segment elevation and negative T waves in the precordial leads in acute pulmonary embolism: insights into serial electrocardiogram changes.

BACKGROUND: Acute pulmonary embolism (APE) is often misdiagnosed as acute coronary syndrome because of the similarity of the presenting symptoms and of the electrocardiogram (ECG) manifestations. In APE, ST-segment elevation (STE) in leads V1 to V3 /V4 , mimicking anteroseptal myocardial infarction, is not a rare phenomenon. Negative T waves (NTW) in the precordial leads mimicking the "Wellens' syndrome" is an important ECG manifestation of APE. The evolution of these ECG changes-STE and NTW-in APE has not been thoroughly studied. METHODS: We present two patient cases with APE and their evolving serial ECGs to analyze the correlation between STE and NTW. RESULTS: NTW developed later than STE in these two patient cases. CONCLUSIONS: NTW might represent a "postischemic" ECG pattern indicating a previous stage with transmural myocardial ischemia.

Electrocardiographic abnormalities in patients with acute pulmonary embolism complicated by cardiogenic shock.

BACKGROUND: Cardiogenic shock (CS) is a predictor of poor prognosis in patients with acute pulmonary embolism (APE). OBJECTIVES: The aim of this study was to compare electrocardiography (ECG) parameters in patients with APE presenting with or without CS. METHODS: A 12-lead ECG was recorded on admission at a paper speed of 25 mm/s and 10 mm/mV amplification. All ECGs were examined by a single cardiologist who was blinded to all other clinical data. All ECG measurements were made manually. RESULTS: Electrocardiographic data from 500 patients with APE were analyzed, including 92 patients with CS. The following ECG parameters were associated with CS: S1Q3T3 sign, (odds ratio [OR]: 2.85, P<.001), qR or QR morphology of QRS in lead V1, (OR: 3.63, P<.001), right bundle branch block (RBBB) (OR: 2.46, P=.004), QRS fragmentation in lead V1 (OR: 2.94, P=.002), low QRS voltage (OR: 3.21, P<.001), negative T waves in leads V2 to V4 (OR: 1.81, P=.011), ST-segment depression in leads V4 to V6 (OR: 3.28, P<.001), ST-segment elevation in lead III (OR: 4.2, P<.001), ST-segment elevation in lead V1 (OR: 6.78, P<.01), and ST-segment elevation in lead aVR (OR: 4.35, P<.01). The multivariate analysis showed that low QRS voltage, RBBB, and ST-segment elevation in lead V1 remained statistically significant predictors of CS. CONCLUSIONS: In patients with APE, low QRS voltage, RBBB, and ST-segment elevation in lead V1 were associated with CS.

Correlation between ECG presentation and cardiovascular magnetic resonance imaging in Takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TTC) is characterized by acute and reversible ventricular dysfunction in the absence of significant coronary artery disease, typically triggered by acute emotional or physical stress. In the acute phase of TTC, the electrocardiogram (ECG) shows ST-segment elevation, which rapidly evolves into negative T waves and QT prolongation. However, different types of ventricular dysfunction may be associated with different patterns of ECG presentation. In this paper, we discuss the correlation between ECG presentation and cardiovascular magnetic resonance imaging in TTC.

ST-segment deviation pattern of takotsubo cardiomyopathy similar to acute pericarditis: diffuse ST-segment elevation.

BACKGROUND: Possible similarities or differences in the ST- and PR-segment deviations in the electrocardiogram of takotsubo cardiomyopathy (TTC) and acute pericarditis (AP) are not well defined. METHODS: We compared different parameters of the admission electrocardiogram in eight patients with TTC and eight patients with AP with ST-segment elevation in the acute phase. RESULTS: We found significant differences in the maximal magnitude of the T wave in the precordial leads, but not in the ST- and PR-segment deviation patterns between the two patient groups. All the patients in the two groups showed consistent ST-segment depression in lead aVR and absence of ST-segment elevation in lead V1. CONCLUSIONS: The ST- and PR-segment deviation patterns in TTC are similar to that of AP, namely diffuse ST-segment elevations with reciprocal changes in aVR and V1 and PR-segment elevation in aVR accompanied by PR-segment depression in the inferior leads, possibly indicating that TTC has ECG characteristics of circumferential subepicardial ischemia in the acute phase.

Prominent precordial T waves as a sign of acute anterior myocardial infarction: electrocardiographic and angiographic correlations.

In clinical practice, one occasionally encounters patients with symptoms lasting for relatively long time showing prominent positive T waves combined with minor ST elevation, or ST depression in the precordial leads. This electrocardiographic pattern has been described as Sclarovsky-Birnbaum grade 1 ischemia. We present 3 cases of patients with predominantly grade 1 ischemia, in whom the culprit site was in the left anterior descending coronary artery. The electro/pathophysiologic mechanisms of these electrocardiographic patterns are discussed.

Does left anterior descending coronary artery acute occlusion proximal to the first septal perforator counteract ST elevation in leads V5 and V6?

The mechanisms of the so-called extensive anterior acute myocardial infarction including ST-segment elevation in leads V(1) (ST upward arrow(V1)) through V(6) (ST upward arrow(V6)) are not clear. This report is focused on the electrocardiographic (ECG) changes in 2 cases with anterior AMI. In case 1, the ECG showed complete right bundle-branch block, left anterior fascicular block, and ST upward arrow(V2) through ST upward arrow(V6) on admission, but 5 minutes later, after the disappearance of complete right bundle-branch block and left anterior fascicular block, a striking ST depression in V6 (ST downward arrow(V6)) and ST upward arrow(V1) occurred. In case 2, the ECG showed ST upward arrow(V1) through ST upward arrow(V6). The physiopathologic mechanisms of these ECG findings are discussed.

Acute anterior wall myocardial infarction entailing ST-segment elevation in lead V3R, V1 or aVR: electrocardiographic and angiographic correlations.

BACKGROUND: The correlation between ST-segment elevation (ST upward arrow) in lead V(3)R (ST upward arrow(V3R)), lead V(1) (ST upward arrow(V1)), and lead aVR (ST upward arrow(aVR)) during anterior wall acute myocardial infarction (AMI) and the culprit lesion site in the left anterior descending (LAD) coronary artery and the nature of the conal branch of the right coronary artery has not been thoroughly described. METHODS: One hundred forty-two patients with first anterior wall AMI were included. The 15-lead electrocardiogram with the standard 12 leads plus leads V(3)R through V(5)R showing the most pronounced ST-segment deviation before initiation of reperfusion therapy was evaluated and correlated with the exact LAD occlusion site in relation to the first septal perforator (S1) and the nature of the conal branch of the right coronary artery as determined by coronary angiography. RESULTS: ST-segment elevation in lead aVR, ST upward arrow(V1) of at least 2 mm, and ST upward arrow(V3R) of at least 1 mm were more prevalent among patients with occlusions proximal to S1 than patients with occlusions distal to S1 (41.7% vs 4.9%, P < .01; 30.0% vs 7.3%, P < .01; and 91.7% vs 4.9%, P < .01, respectively). Of the 60 patients with occlusions proximal to S1, 20 patients had a small conal branch (18 patients with ST upward arrow(aVR) and 15 patients with ST upward arrow(V1) >or=2 mm), and 24 patients had a large conal branch (all patients with non-ST upward arrow(aVR) and ST upward arrow(V1) <2 mm; P < .01). The sensitivity of ST upward arrow(V1) of more than 1 mm, of at least 2 mm, ST upward arrow(V3R) of at least 1.5 mm, and ST upward arrow(aVR) for detecting a small conal branch was 65.1%, 81.8%, 84.0%, and 90%, respectively; the specificity was 68.5%, 64%, 66.7%, and 64.9%, respectively. CONCLUSIONS: In patients with anterior wall AMI, ST upward arrow(V3R) of at least 1 mm combined with ST upward arrow in leads V(2) through V(4) were strongly predictive of LAD occlusion proximal to S1; furthermore, ST upward arrow(aVR) and ST upward arrow(V1) of at least 2 mm were found to be useful in identifying LAD occlusion proximal to S1. ST upward arrow(aVR), ST upward arrow(V3R) of at least 1.5 mm, and ST upward arrow(V1) of at least 2.0 mm were also associated with the presence of a small conal branch not reaching the intraventricular septum during anterior wall AMI.

Updated electrocardiographic classification of acute coronary syndromes.

The electrocardiogram (ECG) findings in acute coronary syndrome should always be interpreted in the context of the clinical findings and symptoms of the patient, when these data are available. It is important to acknowledge the dynamic nature of ECG changes in acute coronary syndrome. The ECG pattern changes over time and may be different if recorded when the patient is symptomatic or after symptoms have resolved. Temporal changes are most striking in cases of ST-elevation myocardial infarction. With the emerging concept of acute reperfusion therapy, the concept ST-elevation/ non-ST elevation has replaced the traditional division into Q-wave/non-Q wave in the classification of acute coronary syndrome in the acute phase. KEYPOINTS: In acute coronary syndrome, in addition to the traditional electrocardiographic risk markers, such as ST depression, the 12-lead ECG contains additional, important diagnostic and prognostic information. Clinical guidelines need to acknowledge certain high-risk ECG patterns to improve patient care.