The prevalence of lateral lead early repolarization in otherwise normal electrocardiograms as a function of age.

The prevalence of early repolarization in otherwise normal electrocardiograms as a function of age was evaluated in 2335 Veteran male patients. Thirty-one percent of the patients <35years of age had early repolarization, whereas only 5% of patients >65years of age demonstrated this phenomenon. In addition, only 12% of female patients <35years of age had early repolarization.

Development of a serial comparison program for conduction defects, acute myocardial infarction, and the use of additional leads.

Serial comparison of electrocardiograms (ECGs) is a useful tool in clinical diagnostic ECG and an enhancement to computer ECG analysis. When an analysis algorithm is modified, the corresponding serial comparison program needs to be updated accordingly. The new Philips diagnostic algorithm increased the number of leads in the ECG from the traditional 12 leads to 16, making it possible to diagnose right ventricular infarct/injury based on right-sided lead V4R. To keep pace with the widespread reperfusion therapy for acute myocardial infarct, the serial comparison program was revised to recognize the rapid ECG changes in patients with ST-elevation myocardial infarct following successful reperfusion therapies. The serial comparison program was also enhanced to split "combined" statements in the category of ventricular conduction delay (includes incomplete ventricular conduction delay and bundle-branch blocks) and compare each of the statements separately.

Preliminary observations using optical coherence tomography to assess neointimal coverage of a metal stent in a porcine model.

BACKGROUND: Concerns surrounding late stent thrombosis have prompted the development of novel imaging techniques to assess neointimal coverage. Recent clinical studies have evaluated optical coherence tomography (OCT) to evaluate neointimal coverage, but pathologic correlation in an animal model is lacking. We assessed the hypothesis that OCT could accurately assess early neointimal coverage in a porcine model. METHODS: OCT imaging of bare metal stents in each coronary artery was performed at implantation (n=6), Day 4 (n=3), and Day 20 (n=3), and images were evaluated at three cross-sections per stented segment. Neointimal strut coverage was categorized by OCT as covered or uncovered, and neointimal thickness was determined (Day 20). Pathological correlation was obtained using scanning electron microscopy (SEM) to assess strut coverage (Day 4) and histomorphometry to quantify neointimal thickness (Day 20). RESULTS: At Day 4, OCT imaging detected 28 (26%) of 109 uncovered struts, and the ratio of uncovered/total strut area by SEM was 31%. All imaging modalities showed complete coverage at Day 20. Mean (+/-SE) neointimal thickness at Day 20 was 109+/-6 microm by OCT (n=116 struts) and 93+/-5 microm by pathology (n=68). Mean neointimal thickness on a segment-by-segment basis determined by OCT correlated with mean histomorphometric analysis (Reviewer 1: r=.74, P=.092 and Reviewer 2: r=0.60, P=.212). CONCLUSIONS: Day 4 represents an important time point for the assessment of early neointimal coverage in the porcine model. OCT imaging accurately assesses the extent and thickness of early neointimal coverage with good pathologic correlation. OCT represents a promising imaging modality for the in vivo assessment of neointimal coverage.

Comparison of the Selvester QRS scoring system applied on standard versus high-resolution electrocardiographic recordings.

A comparison was performed between the points measured using the Selvester QRS scoring system in 60 electrocardiograms (ECGs) displayed in both a standard format as well as a 4-fold magnified (quad-plot) format. Fifty criteria (a maximum possibility of 31 points) were evaluated in each ECG. The data indicate that in 50% of the ECGs, an identical number of points were measured. However, there was a single point difference in 31%, 2 points in 15%, and more than 2 points in 4%. The differences were primarily because of points scored on the quad-plot but not on the standard ECG. Thus, a systematic underestimation of infarct size may occur when the Selvester QRS score is measured manually from a standard ECG.

Computerized serial comparison of electrocardiograms: program performance in myocardial infarction.

Serial comparison of electrocardiograms (ECGs) can provide a useful clinical function by reporting to the editing cardiologist the diagnostic changes that have occurred since the previous ECG. This program detects "significant measurement differences" in each of the diagnostic categories to detect these changes. We evaluated the accuracy and use of this serial comparison program by comparing the diagnostic results of the program with those of an expert cardiologist using a database of ECGs obtained from patients with symptoms admitted to the hospital and other laboratory results consistent with acute myocardial infarction. We found that the level of agreement between the computer and the cardiologist was much higher when a current ECG was compared with a previous that had been edited by the cardiologist than when that same ECG was analyzed in isolation.

Development of an automated Selvester Scoring System for estimating the size of myocardial infarction from the electrocardiogram.

Although the Selvester Scoring System for estimating the size of myocardial infarction from the standard 12-lead electrocardiogram (ECG) has potential clinical value, it has found limited application because of the difficulties in making precise and reproducible measurements. The objective of this study was to develop software to automate the Selvester Scoring System, thus allowing wider application of the technique. The study was carried out using a training set consisting of ECG data recorded from 705 individuals with and without previous myocardial infarction. Algorithms for the 50 criteria in the Selvester Scoring System were iteratively improved by comparison of scores obtained by 2 experienced cardiologist investigators with those generated by the program. The final version was evaluated in a test set consisting of 60 ECGs by comparing scores derived by cardiologist investigator with those obtained by the program. The disagreements occurred only in 1.1% of the score comparisons and in 1.6% of the specific measurements. In all cases in which a disagreement occurred, it resulted from very small differences in measurements. These results indicate that the algorithm for automated application of the Selvester Scoring System is adequate for both clinical and research applications.

Electrocardiography to define clinical status in primary pulmonary hypertension and pulmonary arterial hypertension secondary to collagen vascular disease.

STUDY OBJECTIVES: To determine the utility of the ECG for predicting clinical status in adults with primary pulmonary hypertension (PPH) or pulmonary arterial hypertension (PAH) secondary to collagen vascular disease. DESIGN: Retrospective study. SETTING: Outpatient clinic in a tertiary referral center. PATIENTS: Adult outpatients with PPH or PAH secondary to collagen vascular disease who underwent electrocardiography within 30 days of undergoing right-heart catheterization, echocardiography, and 6-min walk testing. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The following measurements were recorded from each ECG: P-wave amplitude in lead II; mean frontal QRS axis; QRS duration; R-wave and S-wave deflections in leads I and V6; and the T-wave configurations in the precordial leads. These ECG variables were correlated with hemodynamic variables, RV size, and exercise capacity. Of the 61 patients included in this study, 56 (92%) were women. Eight of 61 patients (13%) had normal findings on ECGs. There was no significant difference in the demographics or hemodynamics when comparing groups with normal vs abnormal ECGs. All ECG parameters had no more than moderate correlation with hemodynamic variables, ventricular size measured by echocardiogram, and exercise capacity as measured by a 6-min walk. The best correlation was between mean the frontal QRS axis and cardiac index (r = -0.46). CONCLUSIONS: The ECG is an inadequate screening tool to rule out the presence of clinically relevant pulmonary hypertension, either primary or secondary to collagen vascular disease. The mean frontal QRS axis correlated best with the severity of hemodynamic impairment.