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Biomedical subjects

Gregory M Marcus

Publications and source records attributed to Gregory M Marcus.

12 recordsLinked to original sources
PubMed2007

The utility of gestures in patients with chest discomfort.

PURPOSE: Patient gestures are thought to be useful in determining the etiology of chest discomfort. We sought to determine the utility of certain patient gestures in the diagnosis of ischemic chest discomfort or myocardial infarction. METHODS: We performed a prospective observational study of 202 patients admitted with chest discomfort. Patients were observed for the Levine Sign (clenched fist to the chest), the Palm Sign (palm of the hand to the chest), the Arm Sign (touching the left arm), and, as an indicator of nonischemic chest discomfort, the Pointing Sign (pointing with 1 finger). RESULTS: Prevalences of the Levine, Palm, Arm, and Pointing Signs were 11%, 35%, 16%, and 4%, respectively. Using troponin levels and results of functional studies and coronary angiograms as reference standards, none of the sensitivities of the signs exceeded 38%. Specificities of the Levine and Arm Signs ranged between 78% and 86%, but the positive predictive values did not exceed 55%. The Pointing Sign had a specificity of 98% for evidence of nonischemic chest discomfort, and the positive predictive value of a negative troponin was 88%. The diameter of discomfort significantly correlated with certain gestures. Larger chest pain diameters were associated with evidence of myocardial ischemia. CONCLUSIONS: Although certain gestures are exhibited by patients presenting with chest discomfort, they generally have poor test characteristics. The Pointing Sign has a high specificity for nonischemic chest discomfort, but a low prevalence. The gestures may communicate the size of the chest discomfort, with larger areas suggestive of ischemia.

Biomarkers↗
PubMed2006

Repeat transseptal catheterization after ablation for atrial fibrillation.

INTRODUCTION: A substantial number of patients require a second left atrial procedure after ablation for atrial fibrillation (AF), either for left atrial flutter or recurrent AF. The success and complication rates of repeat transseptal catheterization in these patients are unknown. The aim of this study was to determine the difficulty and/or success rates of repeat transseptal catheterization after left atrial ablation for AF. METHODS AND RESULTS: Consecutive patients undergoing repeat left atrial procedures after ablation for AF over a 1-year period were enrolled. Difficulties with, success rates, and complications of the first and second transseptal catheterizations were recorded. Sixteen patients underwent a repeat transseptal catheterization. Of the 4 in whom the first procedure was performed with an ablation catheter across a patent foramen ovale (PFO), 3 required a transseptal puncture for their repeat procedure. The remaining 12 underwent transseptal puncture without difficulty for their first procedure, and, despite the same operators for each patient, the repeat transseptal was noted to be difficult in 5. Of those 5, the transseptal puncture was unsuccessful due to increased interatrial septal thickness in 2 patients. One repeat transseptal attempt was aborted after posterior right atrial puncture with the transseptal needle occurred, attributed to distorted interatrial septal anatomy not observed prior to the first case. CONCLUSIONS: Compared with the first procedure, repeat transseptal catheterization after ablation for AF, whether initially performed across a PFO or via a transseptal puncture, is more difficult, less often successful, and potentially associated with more complications.

Atrial Fibrillation↗
PubMed2006

Prevalence, patterns of development, and prognosis of right bundle branch block in heart transplant recipients.

Right bundle branch block (RBBB) is the most common electrocardiographic abnormality in heart transplant recipients, but the cause remains unknown, data regarding the prognosis are conflicting, and all previous studies have been limited to <100 patients. This was a study of patients who underwent heart transplantation at Stanford University Medical Center from 1981 to 1995 with known outcomes and >or=2 available electrocardiograms (ECGs). Outcomes were assessed in those with and without conduction disturbances recorded from the ECGs closest to the time of transplantation and the most recent ECGs. Of the 322 heart transplant recipients studied, 141 (44%) died over a mean follow-up of 9 +/- 3.5 years, and 40 (13%) died of sudden cardiac death. In the first ECG obtained, a mean of 1.8 +/- 2.4 years after transplantation, 44 patients (14%) had incomplete RBBB and 26 (8%) had RBBB; in the second ECG, obtained a mean of 5.6 +/- 3.7 years after transplantation, 59 patients (18%) had incomplete RBBB and 63 (20%) had RBBB. Increasing time from transplantation was associated with a greater likelihood for RBBB on the first and second ECGs (p = 0.001 and p <0.0001, respectively). QRS duration, incomplete RBBB, RBBB, or the development of RBBB was not associated with mortality or sudden cardiac death. In conclusion, although RBBB was the most common electrocardiographic abnormality in our study, the prevalence was lower than previously reported. The cause of RBBB appears to be largely related to events that occur well after transplantation, and the prognosis is benign.

Adult↗
PubMed2006

Relationship between accurate auscultation of a clinically useful third heart sound and level of experience.

BACKGROUND: Poor performance by physicians-in-training and interobserver variability between physicians have diminished clinicians' confidence in the value of the third heart sound (S3). METHODS: To determine whether auscultation of a clinically useful S3 improves with advancing levels of experience, we performed a prospective, blinded, observational study of 100 patients undergoing left-sided heart catheterization. Patients underwent blinded auscultation by 4 physicians (each from 1 of 4 different levels of experience), phonocardiography, measurement of blood B-type natriuretic peptide levels, echocardiography for measurement of left ventricular ejection fraction, and cardiac catheterization for measurement of left ventricular end-diastolic pressure. RESULTS: Whereas residents' and interns' auscultatory findings demonstrated no significant agreement with phonocardiographic findings, an S3 auscultated by cardiology fellows (kappa = 0.37; P<.001) and cardiology attendings (kappa = 0.29; P = .003) agreed with phonocardiographic findings. Although the sensitivities of the S3 were low (13%-52%) for identifying patients with abnormal measures of left ventricular function, the specificities were high (85%-95%), with the best test characteristics exhibited by phonocardiography and more experienced physicians. The S3 detected by attendings and fellows was superior in distinguishing an elevated B-type natriuretic peptide level, a depressed left ventricular ejection fraction, or an elevated left ventricular end-diastolic pressure (P = .002-.02 for attendings and .02-.03 for fellows) compared with residents (P = .02-.47) or interns (P = .09-.64). CONCLUSIONS: The S3 auscultated by more experienced physicians demonstrated fair agreement with phonocardiographic findings. Although correlations were superior for phonocardiography, the associations between the S3 and abnormal markers of left ventricular function improved with each level of auscultator experience.

Adult↗
PubMed2006

High-sensitivity C-reactive protein and parameters of left ventricular dysfunction.

BACKGROUND: Elevated levels of high-sensitivity C-reactive protein (CRP), an inflammatory marker, have been associated with heart failure. However, it is not known which parameters of left ventricular dysfunction correlate with elevated levels of CRP. METHODS AND RESULTS: In this cross-sectional study of 98 patients referred for cardiac catheterization, we investigated whether commonly used clinical indices of left ventricular dysfunction correlated with CRP levels. CRP levels were elevated to a greater degree in participants with diabetes mellitus (P =.006) and heart failure (P =.003). Increased CRP levels were associated with increased plasma levels of B-type natriuretic peptide (BNP; P =.0001), decreased left ventricular ejection fraction (LVEF; P =.02), and increased left-ventricular end-diastolic pressure (LVEDP; P =.0005). After multivariable adjustment, LVEDP and CRP were independently associated (P =.046). CONCLUSION: CRP is increased in patients with heart failure. Of the clinical parameters of left ventricular dysfunction, direct measurement of left ventricular end-diastolic pressure is most closely associated with CRP.

Aged↗
PubMed2005

Septal to posterior wall motion delay fails to predict reverse remodeling or clinical improvement in patients undergoing cardiac resynchronization therapy.

OBJECTIVES: The aim of this study was to test the hypothesis that a longer septal-to-posterior wall motion delay (SPWMD) would predict greater reverse remodeling and an improved clinical response in heart failure patients randomized to cardiac resynchronization therapy (CRT) in the CONTAK-CD trial. BACKGROUND: The SPWMD predicted clinical benefit with CRT in two previous studies from the same center. METHODS: In this retrospective analysis of the CONTAK-CD trial, SPWMD was measured from the baseline echocardiogram of 79 heart failure patients (ejection fraction 22 +/- 7%, QRS duration 159 +/- 27 ms, 72% ischemic, 84% male) randomized to CRT and compared with six-month changes in echocardiographic and clinical parameters. Patients with a left ventricular end-systolic volume index (LVESVI) reduction of at least 15% were considered responders. RESULTS: The feasibility and reproducibility of performing the SPWMD measurements were poor. Larger values for SPWMD did not correlate with six-month changes in left ventricular end-diastolic volume index (p = 0.26), LVESVI (p = 0.41), or left ventricular ejection fraction (p = 0.36). Responders did not have a significantly different SPWMD than non-responders (p = 0.26). The SPWMD did not correlate with measures of clinical improvement. At a threshold of SPWMD >130 ms, the test characteristics to predict reverse remodeling or a clinical response were inadequate. CONCLUSIONS: The previous findings that SPWMD predicts reverse remodeling or clinical improvement with CRT were not reproducible in patients randomized in the CONTAK-CD trial.

Aged↗
PubMed2005

Association between phonocardiographic third and fourth heart sounds and objective measures of left ventricular function.

CONTEXT: The third (S3) and fourth (S4) heart sounds detected by phonocardiography are considered to represent the criterion standards of the gallop sounds, but their test characteristics have not been explored. OBJECTIVE: To determine the diagnostic test characteristics of the S3 and S4 for prediction of left ventricular dysfunction using a computerized heart sound detection algorithm. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 90 adult patients undergoing elective left-sided heart catheterization at a single US teaching hospital between August 2003 and June 2004. The mean age was 62 (SD, 13) years (range, 24-90 years) and 61 (68%) were male. Within a 4-hour period, participants underwent computerized heart sound phonocardiographic analysis, cardiac catheterization, transthoracic echocardiography, and blood sampling for assessment of an S3/S4, left ventricular end-diastolic pressure (LVEDP), left ventricular ejection fraction (LVEF), and B-type natriuretic peptide (BNP), respectively. MAIN OUTCOME MEASURES: Diagnostic test characteristics of the computerized phonocardiographic S3 and S4 using markers of left ventricular function as criterion standards. RESULTS: Mean (SD) LVEDP was significantly elevated (18.4 [6.9] mm Hg vs 12.1 [7.3] mm Hg; P<.001), mean (SD) LVEF was reduced (49.4% [20.2%] vs 63.6% [14.8%]; P<.001), and median (interquartile range) BNP was elevated (330 [98-1155] pg/mL vs 86 [41-192] pg/mL; P<.001) in those with an S3, S4, or both compared with patients without a diastolic heart sound. The sensitivities of these heart sounds to detect an elevated LVEDP, reduced LVEF, or elevated BNP were 41%, 52%, and 32% for an S3, and 46%, 43%, and 40% for an S4, respectively. For abnormal levels of the same markers of ventricular function, the specificities of the S3 were 92%, 87%, and 92%, while the specificities of the S4 were 80%, 72%, and 78%, respectively. CONCLUSIONS: Neither the phonocardiographic S3 nor the S4 is a sensitive marker of left ventricular dysfunction. The phonocardiographic S3 is specific for left ventricular dysfunction and appears to be superior to the moderate specificity of the phonocardiographic S4.

Adult↗