Thermogenic supplement use does not alter characteristics of sudden death in the young.

BACKGROUND: To evaluate supplement use, most notably ephedra, which has been temporally associated with sudden death. Animal models suggest increased myocardial irritability may predispose to primary arrhythmic death. METHODS: Clinical, pathological, and investigative records from the Office of the Armed Forces Medical Examiner's Cardiovascular Death Registry were reviewed. Forty-eight cases of those with known supplement use were compared to 144 age-, gender-, and socioeconomic-matched controls in a 1:3 case:control manner. RESULTS: Of the 48 sudden deaths temporally associated with supplement use, the mean age was 34.2 ± 10.0 years and predominantly male (n = 44, 91.7%). The underlying cause of death was fatal atherosclerotic coronary disease in 18 (37.5%), sudden unexplained death in 16 (33.3%), and hypertrophic cardiomyopathy in six (12.5%). Compared with controls, there were no statistically significant differences in adjudicated cause of death. On autopsy, there were no differences in cardiac mass, ventricular wall thickness, or presence of atherosclerosis in those known to be taking identified supplements compared to a control population. In the subject ≥35 years, and known to be taking supplements, there was a significant increase in causality of death as due to sudden unexplained death (relative risk = 5.1 [95% confidence interval, 1.4-18.7]). CONCLUSIONS: Active surveillance of mortality in an autopsy-derived series of young adults finds atherosclerotic coronary disease and idiopathic sudden death are common etiologies of death when taking supplements, but no cardiac structural or histologic mechanism to suggest different pathologic process than a matched control population.

Chest pain, ST elevation, and positive cardiac enzymes in an austere environment: differentiating smallpox vaccination-mediated myocarditis and acute coronary syndrome in Operation Iraqi Freedom.

BACKGROUND: Myocarditis is a recognized but rare complication of smallpox immunization. It typically presents within 30 days of immunization and on initial presentation shares many characteristics with acute coronary syndrome. Electrocardiogram findings, elevated cardiac enzymes, and undifferentiated chest pain require immediate implementation of therapy directed towards an acute coronary syndrome. In an austere environment, access to advanced care may be limited. OBJECTIVES: Smallpox vaccine-mediated myocarditis may present, typically within 30 days of immunization, in such a fashion that it is impossible to distinguish from acute myocardial infarction. The purpose of this article is to alert the clinician to this problem and to provide information to assist in making a suitable diagnosis and disposition in the absence of an absolute diagnosis. CASE REPORT: We present a case of smallpox vaccine-associated myocarditis in an American serviceman deployed in Iraq, and review the literature to determine management of these cases in an emergency setting. CONCLUSIONS: This case serves to increase awareness of the association of vaccine-mediated myocarditis in the month after immunization, and the fact that it may present similar to infarction. If the clinical probability of myocarditis is greater than infarction, this will lead the clinician to different treatment modalities.

Differential manifestation of cardiovascular complaints as a function of utilization of ergogenic supplements.

INTRODUCTION: The rate of use of dietary supplements among young adults is significant. While the military makes significant restrictions on the use of certain pharmacologic drugs and actively tests for illegal drugs in a deployed environment, there is a near-unlimited supply of body-enhancing supplements available at military exchanges to deployed personnel. By emphasizing physical performance and providing these for purchase, the military leadership, perhaps unknowingly, endorses the use of these products. Cardiovascular symptoms represent one of the leading nontraumatic causes of aeromedical evacuation from a combat zone. Whether the use of supplements is associated with a differential presentation to cardiovascular complaint is unknown. METHODS: Retrospective review using the US Department of Defense Military Health System data, we identified patients evaluated for cardiovascular complaints of syncope or palpitations while deployed to Iraq and Afghanistan. RESULTS: There were 905 US military personnel who presented with complaint of syncope or palpitations (mean age 31 +/- 10 years, 77% male). There were 83 (9.2%) who self-reported taking an ergogenic supplement. The incidence of reported use of supplements among males was 10.8%, which was significantly higher than its use among females at 3.8% (P = 0.001). In those >30 years, those on supplements had a higher resting pulse (90 +/- 28 vs 79 +/- 24 beats/min, P = 0.032), and the incidence of resting tachycardia was three-fold higher (35.0% vs 11.4%, P = 0.008). Supplement use was seen in 12.3% of those who presented with palpitations, which was significantly higher than those who presented without palpitations (7.8%, P = 0.043). In those taking supplements, symptoms were more likely during exertion (26.5% vs 15.0%, P < 0.001), and immediately postexertional (13.2% vs 4.6%, P < 0.001). An electrocardiogram was suggestive of diagnosis in 103 (16.3%), while head computed tomography, treadmill, and echocardiogram had no diagnostic utility in this patient population. DISCUSSION: In a healthy population serving within a combat zone, there exists a differential expression of disease in those taking supplements. Further study of a prospective nature to determine the impact of supplement use in this environment may allow for a more refined policy toward use and medical evaluation.

Resource utilization in the management of young patients with syncope in a combat theater of operations.

UNLABELLED: Clinical features of young patients presenting with syncope have been underreported. METHODS: Retrospective review using U.S. Military Health System's Theater Medical Data Store and Joint Medical Workstation identified patients evaluated for syncope from January 2005 to October 2007 while deployed to a combat zone. RESULTS: We identified 848 patients with syncope. The majority (80.8%) were under the age of 40. The diagnostic yield of the ECG was 2.0%. In those <40 years, there were no head CTs or transthoracic echocardiograms that identified a cause of syncope. There was no difference in evacuation out of theater between those <40 years and those >40 years (10.8% vs. 8.6%, p = 0.08). Patients with a prior episode of syncope were more likely to undergo medical evacuation outside of the combat zone (16.0% vs. 7.7%, p < 0.01). DISCUSSION: Evacuation of those <40 years to facilities with advanced imaging did not add diagnostic information.

Association of electrocardiographic morphology of exercise-induced ventricular arrhythmia with mortality.

BACKGROUND: The prognostic importance of exercise-induced ventricular arrhythmia (EIVA) may be confounded by the presence of lower-risk idiopathic right ventricular outflow tract arrhythmias with left bundle-branch block (LBBB) morphology. OBJECTIVE: To determine whether right bundle-branch block (RBBB)-morphology EIVA was associated with increased mortality. DESIGN: Retrospective cohort. SETTING: Academic medical center. PATIENTS: 585 unique patients with EIVA and 2340 patients without EIVA, matched by age, sex, and risk factor, who were referred for exercise testing in an academic medical center. MEASUREMENTS: Deaths and ischemia and infarction found on perfusion scan. RESULTS: During a mean follow-up of 24 months (SD, 13), 31 deaths occurred in the EIVA group compared with 43 deaths in the group without EIVA (5.3% vs. 1.8%; P < 0.001). Worse survival in patients with RBBB-morphology or multiple-morphology EIVA (6.9%) than in patients without EIVA caused this difference. Patients with LBBB-morphology EIVAs had a mortality rate (2.5%) similar to that of patients without EIVA (P = 0.93, log-rank test). Among patients without known atherosclerotic coronary artery disease, any RBBB-morphology EIVA was associated with death (hazard ratio, 2.73 [95% CI, 1.78 to 4.13]; P < 0.001), but LBBB-morphology EIVA was not (hazard ratio, 0.82 [CI, 0.18 to 2.04]; P = 0.72). LIMITATIONS: Not all LBBB-morphology EIVA can be dismissed, and not all RBBB-morphology EIVA is high risk. Further evaluation of patients for structural heart disease was clinically driven, not protocol-driven. CONCLUSION: Right bundle-branch block- or multiple-morphology EIVA is associated with increased mortality. Inclusion of patients with isolated LBBB-morphology EIVA, which often is idiopathic, may contribute to differences in the prognostic importance of EIVA in previous studies.

Sustained ventricular tachycardia associated with corrective valve surgery.

BACKGROUND: The causes of sustained monomorphic ventricular tachycardia (VT) after cardiac valve surgeries have not been studied extensively, although bundle-branch reentry has been reported. METHODS AND RESULTS: Records of 496 patients referred for electrophysiology study and catheter ablation of recurrent VT were reviewed. Twenty patients (4%) had VT after aortic or mitral valve surgery in the absence of known myocardial infarction. The median age was 53 years, and the median ejection fraction was 45%. In 4 patients, VT occurred early after surgery, and electrophysiology study was performed 3 to 10 days later. In the remaining patients, electrophysiology study was performed a median of 12 years (interquartile range 5 to 15 years) after surgery. Sustained VT was inducible in 17 patients. VT was attributed to scar-related reentry in 14 patients (70%) and to bundle-branch reentry in 2 (10%). Multiple VTs were present in 9 of 14 patients with scar-related reentry. A total of 42 induced VTs were targeted for ablation. Of the 14 patients with scar-related reentry, 9 (64%) had periannular scar, and 10 (71%) had an identifiable endocardial circuit isthmus. Ablation abolished 41 (98%) of the 42 targeted VTs. At a median follow-up of 2.1 years, 3 deaths occurred 8 to 14 months after ablation. One patient with incessant VT early after valve surgery suffered a stroke with residual hemianopsia. Of the 20 patients, 3 required repeat ablation after recurrence, and 2 of these who were not inducible during electrophysiology study had clinical recurrence that necessitated ablation. CONCLUSIONS: Sustained VT after valve surgery appears to be bimodal in presentation, occurring either early after surgery or years later. In this referral population, reentry in a region of scar is more common than bundle-branch reentry. Catheter ablation can be successful.

Complete heart block following penetrating chest trauma in operation Iraqi freedom.

We present a 30-year-old US army soldier who had penetrating chest trauma from a road side explosive with focal cardiac injury. The soldier had penetration of his right atrium and subsequent traumatic membranous ventricular septal defect and complete heart block. He was brought to a Combat Support Hospital where fortuitously the assigned trauma surgeon on-call was a cardiothoracic surgeon, and the assigned trauma intensivist on-call was a cardiac electrophysiologist. Of course, the only source they knew of a pacemaker was halfway around the world. We discuss the management of this injury in an austere combat environment.

Causes of sudden death in young female military recruits.

This study sought to examine the incidence of sudden death in a large, multiethnic cohort of young women. Approximately 852,300 women entered basic military training from 1977 to 2001. During this period, there were 15 sudden deaths in female recruits (median age 19 years, 73% African-American), occurring at a median of 25 days after arrival for training. Of the sudden deaths, 13 (81%) were due to reasons that may have been cardiac in origin. Presumed arrhythmic sudden death in the setting of a structurally normal heart was seen in 8 recruits (53%), and anomalous coronary origins were found in 2 recruits (13%). The mortality rate was 11.4 deaths per 100,000 recruit-years (95% confidence interval 6.9 to 18.9). The rate was significantly higher for African-American female recruits (risk ratio 10.2, p <0.001). Sudden death with a structurally normal heart was the leading cause of death in female recruits during military training.

Mortality following defibrillator implantation in patients with renal insufficiency.

INTRODUCTION: Patients with renal insufficiency have an increased risk of atherosclerotic coronary artery disease, cardiovascular events, and sudden cardiac death. Due to under-representation of patients with renal disease in large clinical trials, outcomes of implantable cardioverter defibrillator (ICD) implantation in this group remain unclear. METHODS AND RESULTS: Inpatient and ambulatory records were reviewed for 741 consecutive patients undergoing 947 defibrillator implants or replacements at Department of Defense Medical Facilities. Demographics, medical history, and mortality were reviewed. The mean age of the cohort was 64 +/- 14 years and 599 (80.8%) were male. There were 173 patients (23.3%) with chronic renal insufficiency, 22 (3.0%) undergoing hemodialysis, and 546 (73.7%) without reported renal disease. The mean number of annual hospital admissions for heart failure among patients with and without renal failure was 3.8 +/- 4.0 versus 1.2 +/- 1.9 (P < 0.0001), respectively. The 1-year survival for those without renal insufficiency was 96.6%, compared to 87.8% for those with chronic renal insufficiency, and 88.7% for those undergoing hemodialysis. Multivariate analysis demonstrated a significant association between mortality among ICD patients and renal insufficiency, independent of coexisting congestive heart failure, ischemic cardiomyopathy, and diabetes mellitus (P < 0.0001). CONCLUSIONS: Among ICD recipients, those with renal insufficiency have a significantly higher mortality rate than those without renal insufficiency. Among a cohort of patients with ICDs, those with known renal insufficiency have higher rates of health care resource utilization and more heart failure admissions. Development of a national registry for ICDs should include data with regard to renal function.

Peripheral blood levels of matrix metalloproteinases in patients referred for percutaneous balloon mitral valve commissurotomy.

BACKGROUND AND AIM OF THE STUDY: Inflammation may play a central role in the progression of stenotic valvular heart disease. Serum levels of matrix metalloproteinases (MMPs), markers of extracellular matrix (ECM) turnover and potential markers of active inflammation, have been recently demonstrated in several inflammatory processes. The present study was designed to examine whether systemic evidence of ECM turnover was present in advanced stenotic mitral valve disease. METHODS: Serum levels of MMP-1, -3 and -9 were measured in 114 patients with mitral stenosis referred for percutaneous balloon mitral valve commissurotomy, and compared to those in 48 healthy, age- and gender-matched controls. RESULTS: Serum levels of MMP-1, -3 and -9 did not vary according to hemodynamic profile or heart failure class at the time of blood sampling. Levels of MMP-1 and -3 were not significantly different between those patients with mitral stenosis and controls. The level of MMP-9 was significantly higher in patients with mitral stenosis than in controls, and did not appear to be altered by commissurotomy. CONCLUSION: Serum levels of MMP-9 were elevated in patients with mitral stenosis, providing further evidence that inflammation and ECM remodeling plays an important role in the pathophysiology of valvular heart disease.

The cardiovascular patient's perceptions of complementary and alternative medicine.

BACKGROUND: Complementary and alternative medicine (CAM) use is common among patients with cardiovascular disorders and is generally underrecognized by physicians. The attitudes of these patients regarding these therapies and their perceptions of safety and efficacy have not been well defined. METHODS: A written survey was received from a cohort of outpatients seen at a large outpatient cardiovascular clinic in Texas. Over 75% of patients responded, with more than 90% of returned surveys adequate for analysis. RESULTS: Of the 210 respondents 113 admitted to CAM use, with Vitamins E and C being the most frequently utilized agents. Women were significantly more likely to take CAM than men (69 vs. 46%, p = 0.002), particularly those taking hormone replacement therapy. Over half of patients surveyed stated their cardiologist was unaware of their use of CAM. Only 15% of patients felt that CAM was more efficacious than their traditional medications, but almost half felt it was significantly safer. A similar number were unaware of any interactions between CAM and their other medications. CONCLUSIONS: Use of CAM is common in cardiology outpatients, and many patients remain unaware of potential health risks. Physicians should routinely question patients about use of CAM and attempt to educate users regarding potential health risks.

Direct admission to cardiology for patients hospitalized for atrial fibrillation reduces length of stay and increases guideline adherence.

OBJECTIVE: We hypothesized that a clinical pathway for inpatient management of atrial fibrillation on a cardiology service would result in improved resource utilization. METHODS: In July 2002, an evidence-based pathway was developed for treatment of patients hospitalized for atrial fibrillation. Guidelines directed patient care from admission from the emergency department to inpatient management on a cardiology service. Ancillary testing, anticoagulation, and inpatient length of stay were then compared before and after institution of the pathway. RESULTS: The overall length of stay was significantly shorter for patients admitted through the pathway (43.0 hours vs. 82.0 hours, p < 0.01). After the pathway, there was increased use of transesophageal echocardiography and a trend toward increased use of warfarin. CONCLUSIONS: Patients requiring hospitalization for symptomatic atrial fibrillation had a nearly 50% reduction in length of stay, with a trend toward increased utilization of risk-appropriate antithrombotic therapy, if they were directly admitted through cardiology via a clinical pathway.

Cardiovascular Complaints Among Military Members During Operation Enduring Freedom.

During Operation Enduring Freedom, the US military began deploying a dedicated theater cardiology consultant to Afghanistan in an effort to increase rates of return to duty in service members with cardiovascular complaints. This study was designed to categorize these complaints and determine the effect on both aeromedical evacuation and return to duty rates during a 2.5 year observation period. A total of 1,495 service members were evaluated, with 43% presenting due to chest pain followed by arrhythmias/palpitations (24.5%) and syncope (13.5%). Eighty-five percent of individuals returned to duty, most commonly with complaints of noncardiac chest pain, palpitations, or abnormal electrocardiograms. Fifteen percent were evacuated out of theater, most often with acute coronary syndrome, pulmonary embolus, or ventricular tachycardia. The forward-deployed theater cardiology consultant is vital in the disposition of military members by effectively parsing out life threatening cardiovascular conditions versus low risk diagnoses that can safely return to duty.

Incidence and follow-up of inflammatory cardiac complications after smallpox vaccination.

OBJECTIVES: The purpose of this study was to assess the follow-up of patients with vaccinia-associated myocarditis. BACKGROUND: With the threat of biological warfare, the U.S. Department of Defense resumed a program for widespread smallpox vaccinations on December 13, 2002. One-year afterwards, there has been a significant increase in the occurrence of myocarditis and pericarditis among those vaccinated. METHODS: Cases were identified through sentinel reporting to military headquarters, systematic surveillance, and spontaneous reports. RESULTS: A total of 540,824 military personnel were vaccinated with a New York City Board of Health strain of vaccinia from December 2002 through December 2003. Of these, 67 developed myopericarditis at 10.4 +/- 3.6 days after vaccination. The ST-segment elevation was noted in 57%, mean troponin on admission was 11.3+/- 22.7 ng/dl, and peak cardiac enzymes were noted within 8 h of presentation. On follow-up of 64 patients (96%) at a mean of 32 +/- 16 weeks, all patients had objective normalization of echocardiography, electrocardiography, laboratory testing, graded exercise testing, and functional status; 8 (13%) reported atypical, non-limiting persistent chest discomfort. CONCLUSIONS: Post-vaccinial myopericarditis should be considered in patients with chest pain within 30 days after smallpox vaccination. Normalization of echocardiography, electrocardiography, and treadmill testing is expected, and nearly all patients have resolution of chest pain on follow-up.

Comparison of clinical presentation of acute myocarditis following smallpox vaccination to acute coronary syndromes in patients <40 years of age.

Smallpox vaccine-associated myopericarditis may have a similar presentation to acute coronary syndrome (ACS). The clinical records of 78 young patients (<40 years of age) presenting with ACS (n = 16) or myocarditis after smallpox vaccination (n = 62) were reviewed. Comparisons were made among clinical presentation, cardiac enzymes, echocardiographic findings, and electrocardiographic changes. The presence of cardiac risk factors or focal wall motion abnormalities on echocardiography were associated with a diagnosis of ACS. There was a trend toward earlier elevation of troponin-I and creatine kinase in patients with myocarditis compared with ACS.

Usefulness of programmed ventricular stimulation in predicting future arrhythmic events in patients with cardiac sarcoidosis.

The utility of programmed ventricular stimulation to predict future arrhythmic events in patients with cardiac sarcoidosis is unknown. Similarly, the long-term benefit of implantable cardioverter-defibrillators (ICDs) in cardiac sarcoidosis has not been established. Thirty-two consecutive patients with cardiac sarcoidosis underwent programmed ventricular stimulation. Patients with spontaneous or inducible sustained ventricular arrhythmias (n = 12) underwent ICD insertion. All study patients were followed for the combined arrhythmic event end point of appropriate ICD therapies or sudden death. Mean length of follow-up to sustained ventricular arrhythmia or sudden death was 32 +/- 30 months. Five of 6 patients (83%) with spontaneous sustained ventricular arrhythmias and 4 of 6 patients (67%) without spontaneous but with inducible sustained ventricular arrhythmias received appropriate ICD therapy. Two of 20 patients (10%) with neither spontaneous nor inducible sustained ventricular arrhythmias experienced sustained ventricular arrhythmias or sudden death. Programmed ventricular stimulation predicted subsequent arrhythmic events in the entire population (relative hazard 4.47, 95% confidence interval [CI] 1.30 to 15.39) and in patients who presented without spontaneous sustained ventricular arrhythmias (relative hazard 6.97, 95% CI 1.27 to 38.27). No patient with an ICD died of a primary arrhythmic event. In patients with spontaneous or inducible sustained ventricular arrhythmias, mean survival from first appropriate ICD therapy to death or cardiac transplant was 60 +/- 46 months, with only 2 patients dying or reaching transplant at study end. In conclusion, programmed ventricular stimulation identifies patients with cardiac sarcoidosis at high risk for future arrhythmic events. ICDs effectively terminate life-threatening arrhythmias in high-risk patients, with significant survival after first appropriate therapy.

Relation of QTc duration heterogeneity to mortality following orthotopic heart transplantation.

Studies of heart failure patients have demonstrated that serial QT prolongation and abnormally prolonged QT intervals are associated with greater mortality. Serial QT interval measurements in patients who undergo orthotopic heart transplantation (OHT) may quantify the degree of myocardial repolarization heterogeneity and serve as a marker of arrhythmogenic substrate. In this study, the mean survival for those with "stable" QT(c) intervals (a change of -10 to 10 ms/year) was 124 +/- 8 months versus 63 +/- 25 months in those with annual QT(c) changes of >10 ms (p = 0.009). Ventricular repolarization heterogeneity may serve as a marker of identifying high-risk patients after OHT.

Appreciation of precordial cardiac murmur on examination relative to knowledge of valvular heart disease.

Skills associated with physical examination have continued to decline as practitioners have become increasingly reliant on advanced imaging modalities. Our study sought to determine if documentation of valvular heart disease on echocardiography resulted in an increased appreciation and documentation of precordial murmur.

Sudden death in young adults: a 25-year review of autopsies in military recruits.

BACKGROUND: Sudden death among military recruits is a rare but devastating occurrence. Because extensive medical data are available on this cross-sectional and diverse population, identification of the underlying causes of sudden death may promote health care policy to reduce the incidence of sudden death. OBJECTIVE: To determine the causes of nontraumatic sudden death among a cohort of military recruits. DESIGN: Retrospective cohort study using demographic and autopsy data from the Department of Defense Recruit Mortality Registry. SETTING: Basic military training. PATIENTS: All nontraumatic sudden deaths from a monitored 6.3 million men and women age 18 to 35 years. MEASUREMENTS: Descriptive analysis, crude mortality rates of causes of sudden death, and frequency of events as a function of cause of death. RESULTS: Of 126 nontraumatic sudden deaths (rate, 13.0/100,000 recruit-years), 108 (86%) were related to exercise. The most common cause of sudden death was an identifiable cardiac abnormality (64 of 126 recruits [51%]); however, a substantial number of deaths remained unexplained (44 of 126 recruits [35%]). The predominant structural cardiac abnormalities were coronary artery abnormalities (39 of 64 recruits [61%]), myocarditis (13 of 64 recruits [20%]), and hypertrophic cardiomyopathy (8 of 64 recruits [13%]). An anomalous coronary artery accounted for one third (21 of 64 recruits) of the cases in this cohort, and, in each, the left coronary artery arose from the right (anterior) sinus of Valsalva, coursing between the pulmonary artery and aorta. LIMITATIONS: This cohort underwent a preenlistment screening program that included history and physical examination; this may have altered outcomes. CONCLUSIONS: Cardiac abnormalities are the leading identifiable cause of sudden death among military recruits; however, more than one third of sudden deaths remain unexplained after detailed medical investigation.

Addition of right-sided and posterior precordial leads during stress testing.

BACKGROUND: Exercise treadmill testing has limited sensitivity for the detection of coronary artery disease, frequently requiring the addition of imaging modalities to enhance the predictive value of the test. Recently, there has been interest in using nonstandard electrocardiographic (ECG) leads during exercise testing. METHODS: We consecutively enrolled all patients undergoing exercise myocardial imaging with four additional leads recorded (V4R, V7, V8, and V9). The test characteristics of the 12-lead, the 15-lead (12-lead, V7, V8, V9), and the 16-lead (12-lead, V4R, V7, V8, V9) ECGs were compared with stress imaging in all patients. In the subset of patients who underwent angiography within 60 days of stress testing, these lead arrays were compared with the catheterization findings. RESULTS: There were 727 subjects who met entry criteria. The mean age was 58.5 +/- 12.3 years, and 366 (50.3%) were women. Pretest probability for disease was high in 241 (33.1%), intermediate in 347 (47.7%), and low in 139 (19.1%). A total of 166 subjects had an abnormal 12-lead ECG during exercise. The addition of 3 posterior leads to the standard 12-lead ECG resulted in 7 additional subjects having an abnormal electrocardiographic response to exercise. The addition of V4R resulted in only 1 additional patient having an abnormal ECG during exercise. The sensitivity of the ECG for detecting ischemia as determined by stress imaging was 36.6%, 39.2%, and 40.0% (P = NS) for the 12-lead, 15-lead, and 16-lead ECGs, respectively. In those with catheterization data (n = 123), the sensitivity for determining obstructive coronary artery disease was 43.5%, 45.2%, and 45.2% (P = NS) for the 12-lead, 15-lead, and 16-lead ECGs, respectively. The sensitivity of imaging modalities was 77.4% when compared with catheterization. CONCLUSIONS: In patients undergoing stress imaging studies, the addition of right-sided and posterior leads did not significantly increase the sensitivity of the ECG for the detection of myocardial ischemia. Additional leads should not be used to replace imaging modalities for the detection of coronary artery disease.