Jo Mahenthiran

Significance of a Fragmented QRS Complex Versus a Q Wave in Patients With Coronary Artery Disease

Background— Q waves on a 12-lead ECG are markers of a prior myocardial infarction (MI). However, they may regress or even disappear over time, and there is no specific ECG sign of a non–Q-wave MI. Fragmented QRS complexes (fQRSs), which include various RSR′ patterns, without a typical bundle-branch block are markers of altered ventricular depolarization owing to a prior myocardial scar. We postulated that the presence of an fQRS might improve the ability to detect a prior MI compared with Q waves alone by ECG. Methods and Results— A cohort of 479 consecutive patients (mean±SD age, 58.2±13.2 years; 283 males) who were referred for nuclear stress tests was studied. The fQRS included various morphologies of the QRS (<120 ms), which included an additional R wave (R′) or notching in the nadir of the S wave, or >1 R′ (fragmentation) in 2 contiguous leads, corresponding to a major coronary artery territory. The Q wave was present in 71 (14.8%) patients, an fQRS was present in 191 (34.9%) patients, and an fQRS and/or a Q wave was present in 203 (42.3%) patients. Sensitivity, specificity, and the negative predictive value for myocardial scar as detected by single photon emission computed tomography analysis were 36.3%, 99.2%, and 70.8%, respectively, for the Q wave alone; 85.6%, 89%, and 92.7%, respectively, for the fQRS; and 91.4%, 89%, and 94.2%, respectively, for the Q wave and/or fQRS. Conclusions— The fQRS on a 12-lead ECG is a marker of a prior MI, defined by regional perfusion abnormalities, which has a substantially higher sensitivity and negative predictive value compared with the Q wave.

Fragmented wide QRS on a 12-lead ECG: a sign of myocardial scar and poor prognosis.

Background— Fragmented QRS (duration <120 ms) on a 12-lead ECG represents myocardial scar in patients with coronary artery disease. However, the significance of fragmented QRS has not been defined in the presence of a wide QRS (wQRS; duration ≥120 ms). We postulate that fragmented wQRS (f-wQRS) due to bundle branch block, premature ventricular complexes, or paced rhythms (f-pQRS) signify myocardial scar and higher mortality. Methods and Results— Patients who underwent cardiac evaluation with nuclear stress imaging or cardiac catheterization and had wQRS (bundle branch block, premature ventricular complex, or pQRS) were studied. f-wQRS was defined by the presence of >2 notches on the R wave or the S wave and had to be present in ≥2 contiguous inferior (II, III, aVF), lateral (I, aVL, V6) or anterior (V1 to V5) leads. ECG analyses of 879 patients (age, 66.7±11.4 years; male, 97%; mean follow-up, 29±18 months) with bundle branch block (n=310), premature ventricular complex (n=301), and pQRS (n=268) revealed f-wQRS in 415 (47.2%) patients. Myocardial scar was present in 440 (50%) patients. The sensitivity, specificity, positive predictive value, and negative predictive value of f-wQRS for myocardial scar were 86.8%, 92.5%, 92.0%, and 87.5%, respectively. The sensitivity and specificity for diagnosing myocardial scar were 88.6% and 94.4%, 81.4% and 88.4%, and 89.8% and 95.7% for f-bundle branch block, f-premature ventricular complex, and f-pQRS, respectively. f-wQRS was associated with mortality after adjusting for age, ejection fraction, and diabetes ( P =0.017). Conclusions— f-wQRS on a standard 12-lead ECG is a moderately sensitive and highly specific sign for myocardial scar in patients with known or suspected coronary artery disease. f-wQRS is also an independent predictor of mortality. Received January 3, 2008; accepted July 2, 2008.Background—Fragmented QRS (duration <120 ms) on a 12-lead ECG represents myocardial scar in patients with coronary artery disease. However, the significance of fragmented QRS has not been defined in the presence of a wide QRS (wQRS; duration ≥120 ms). We postulate that fragmented wQRS (f-wQRS) due to bundle branch block, premature ventricular complexes, or paced rhythms (f-pQRS) signify myocardial scar and higher mortality. Methods and Results—Patients who underwent cardiac evaluation with nuclear stress imaging or cardiac catheterization and had wQRS (bundle branch block, premature ventricular complex, or pQRS) were studied. f-wQRS was defined by the presence of >2 notches on the R wave or the S wave and had to be present in ≥2 contiguous inferior (II, III, aVF), lateral (I, aVL, V6) or anterior (V1 to V5) leads. ECG analyses of 879 patients (age, 66.7±11.4 years; male, 97%; mean follow-up, 29±18 months) with bundle branch block (n=310), premature ventricular complex (n=301), and pQRS (n=268) revealed f-wQRS in 415 (47.2%) patients. Myocardial scar was present in 440 (50%) patients. The sensitivity, specificity, positive predictive value, and negative predictive value of f-wQRS for myocardial scar were 86.8%, 92.5%, 92.0%, and 87.5%, respectively. The sensitivity and specificity for diagnosing myocardial scar were 88.6% and 94.4%, 81.4% and 88.4%, and 89.8% and 95.7% for f-bundle branch block, f-premature ventricular complex, and f-pQRS, respectively. f-wQRS was associated with mortality after adjusting for age, ejection fraction, and diabetes (P=0.017). Conclusions—f-wQRS on a standard 12-lead ECG is a moderately sensitive and highly specific sign for myocardial scar in patients with known or suspected coronary artery disease. f-wQRS is also an independent predictor of mortality.

Usefulness of Fragmented QRS on a 12-Lead Electrocardiogram in Acute Coronary Syndrome for Predicting Mortality

Electrocardiographic signs of a non-ST elevation myocardial infarction (NSTEMI) are nonspecific, and therefore the diagnosis of NSTEMI during acute coronary syndromes (ACS) depends mainly on cardiac biomarker levels. Fragmented QRS (fQRS) represents myocardial conduction abnormalities due to myocardial infarction (MI) scars in patients with coronary artery disease. However, the time of appearance of fQRS during ACS has not been investigated. It was postulated that in patients with ACS, fQRS on 12-lead electrocardiography occurs within 48 hours of presentation with NSTEMI as well as ST elevation MI and that fQRS predicts mortality. Serial electrocardiograms from 896 patients with ACS (mean age 62 +/- 11 years, 98% men) who underwent cardiac catheterization were studied. Four hundred forty-one patients had MIs, including 337 patients with NSTEMIs, and 455 patients had unstable angina (the control group). Serial electrocardiograms were obtained every 6 to 8 hours during the first 24 hours after the diagnosis of MI and the next day (<48 hours). Fragmented QRS on 12-lead electrocardiography was defined by the presence of single or multiple notches in the R or S wave, without a typical bundle branch block, in > or =2 contiguous leads in 1 of the major coronary artery territories. Fragmented QRS developed in 224 patients (51%) in the MI group and only 17 (3.7%) in the control group (p <0.001). New Q waves developed in 122 (28%), 76 (23%), and 2 (0.4%) patients in the MI, NSTEMI, and control groups, respectively. The sensitivity values of fQRS for ST elevation MI and NSTEMI were 55% and 50%, respectively. The specificity of fQRS was 96%. Kaplan-Meier survival analysis revealed that patients with fQRS had significantly decreased times to death compared to those without fQRS. Fragmented QRS, T-wave inversion, and ST depression were independent predictors of mortality during a mean follow-up period of 34 +/- 16 months. In conclusion, fQRS on 12-lead electrocardiography is a moderately sensitive but highly specific sign for ST elevation MI and NSTEMI. Fragmented QRS is an independent predictor of mortality in patients with ACS.

Perioperative Risk Predictors of Cardiac Outcomes in Patients Undergoing Liver Transplantation Surgery

Background— Cardiac risk assessment for perioperative outcomes of liver transplantation patients is limited. We examined the outcomes of an older intermediate-cardiac-risk group of patients undergoing liver transplantation surgery. Methods and Results— Patients who had liver transplantation surgery between 2001 and 2005 were studied. The 3 outcomes analyzed were nonfatal myocardial infarction, death, and either outcome within the first 30 days after the liver transplantation surgery. Of 403 patients (mean age, 52±9 years; 67% male), 106 (26%) were diabetic, 84 (21%) were hypertensive, and 173 (43%) had a history of smoking. There were 48 total events (12%), 25 myocardial infarctions (7%), and 38 deaths (9%) recorded during the perioperative period. From the final multivariate model, history of coronary artery disease, prior stroke, and postoperative sepsis predicted greater risk (P=0.014; odds ratio [OR], 4.0; 95% confidence interval [CI], 1.3 to 11.8; P=0.025; OR, 6.6; 95% CI, 1.3 to 33.8; and P<0.001; OR, 7.5; 95% CI, 3.3 to 17.1, respectively). Use of perioperative β-blockers was protective (P=0.004; OR, 0.20; 95% CI, 0.1 to 0.6) for combined cardiac outcomes. For the outcome of death on multivariate analysis, postoperative sepsis and increased interventricular septal thickness predicted risk (P<0.001; OR, 8.6; 95% CI, 3.5 to 20.9; and P=0.027; OR, 2.8; 95% CI, 1.1 to 7.2, respectively), whereas the use of perioperative β-blockers was again protective (P=0.012; OR, 0.07; 95% CI, 0.01 to 0.56). Conclusions— In our study of cardiac risk assessment for liver transplantation surgery, history of stroke, coronary artery disease, postoperative sepsis, and increased interventricular septal thickness were markers of adverse perioperative cardiac outcomes, whereas use of perioperative β-blockers was significantly protective.

Fragmented QRS Complexes on 12‐Lead ECG: A Marker of Cardiac Sarcoidosis as Detected by Gadolinium Cardiac Magnetic Resonance Imaging

Background: Fragmented QRS complexes (fQRS) on a 12‐lead ECG are a marker of myocardial scar in patients with coronary artery disease. Cardiac sarcoidosis is also associated with myocardial granuloma formation and scarring. We evaluated the significance of fQRS on a 12‐lead ECG compared to Gadolinium‐delayed enhancement images (GDE) in cardiac magnetic resonance imaging (CMR).

Current noninvasive imaging techniques for detection of coronary artery disease

The development and widespread use of noninvasive imaging techniques have contributed to the improvement in evaluation of patients with known or suspected coronary artery disease. Stress echocardiography and single-photon computed tomography are well-established noninvasive techniques with a proven track record for the diagnosis of coronary atherosclerosis. These modalities are generally widely available and provide a relatively high sensitivity and specificity along with an incremental value over clinical risk factors for detection of coronary artery disease. PET has a high diagnostic performance but continues to have limited clinical use because of the high expense of the dedicated equipment and difficulties in obtaining adequate radionuclides. Cardiac MRI and multislice computed tomography constitute the most recent addition to the cardiac imaging armamentarium. Cardiac MRI offers a comprehensive cardiac evaluation, which includes wall-motion analysis, myocardial tissue morphology, rest and stress first-pass myocardial perfusion, as well as ventricular systolic function. Cardiac computed tomography allows coronary calcium scanning along with noninvasive anatomic assessment of the coronary tree. It can be combined with functional imaging to provide a complete evaluation of the presence and physiological significance of the atherosclerotic coronary disease. No single imaging modality has been proven to be superior overall. Available tests all have advantages and drawbacks, and none can be considered suitable for all patients. The choice of the imaging method should be tailored to each person based on the clinical judgment of the a priori risk of cardiac event, clinical history and local expertise.

Noninvasive imaging techniques of constrictive pericarditis

Constrictive pericarditis (CP) is the result of scarring and loss of elasticity of the pericardial sac, resulting in external impedance of cardiac filling. It can occur after virtually any pericardial disease process. Patients typically present with signs and symptoms of right heart failure and/or low cardiac output. An important pathophysiological hallmark of CP is exaggerated ventricular interdependence and impaired diastolic filling. Echocardiography is the initial imaging modality for diagnosis of CP. Unfortunately, no echocardiographic sign or combination of signs is pathognomonic for CP. CT scan and cardiac MRI are other imaging techniques that can provide incremental diagnostic information. CT scan can easily detect pericardial thickening and calcification, while cardiac MRI provides a comprehensive evaluation of the pericardium, myocardium and cardiac physiology. Occasionally, a multimodality approach needs to be considered for the conclusive diagnosis of CP.

Segmental wall-motion abnormalities of the left ventricle predict arrhythmic events in patients with nonischemic cardiomyopathy

BACKGROUND Nonischemic dilated cardiomyopathy (NICM) is associated with diffuse global hypokinesia on echocardiography. However, NICM also may be associated with segmental wall-motion abnormalities (SWMAs) even in the presence of global hypokinesia, probably secondary to patchy myocardial scars. OBJECTIVE Because myocardial scars serve as substrate for reentry, the purpose of this study was to determine whether SWMA is a predictor of ventricular arrhythmic events in NICM. METHODS Echocardiographic parameters and appropriate implantable cardioverter-defibrillator (ICD) therapy for arrhythmic events (shock or antitachycardia pacing) were studied in NICM patients with an ICD. Two-dimensional echocardiography of the left ventricle was recorded in a 16-segment model. SWMA was defined by the presence of akinesia or moderate to severe hypokinesia in at least two segments. Patients were divided into one of two groups according to the presence (SWMA group) or the absence (non-SMWA group) of SWMA. RESULTS SWMA was present in 47.5% of 101 patients (mean age 58.0 ± 15.6 years, 85% male, primary prophylaxis indication 46%, mean ejection fraction 26% ± 9%, mean follow-up 29 ± 18.4 months) studied. No significant difference in mean age, ejection fraction, and QRS duration was seen between SWMA and non-SWMA groups. The SWMA group had a significantly higher incidence of arrhythmic events than did the non-SWMA group (65% vs 15%, P <.001). Kaplan-Meier survival analysis revealed that SMWA was associated with significantly reduced time to first arrhythmic event (P = .001). SWMA (P <0.001), New York Heart Association heart failure class (P = .016), and secondary prevention indication for ICD placement (P = .005) were significant independent predictors of an arrhythmic event. SWMA did not predict mortality. CONCLUSION SWMA is an independent predictor of arrhythmic events in patients with NICM.

2064 Fragmented QRS complexes on 12-lead ECG as a marker of greater myocardial infiltration by cardiac magnetic resonance gadolinium-delayed enhancement images in patients with sarcoidosis

Background In our study we demonstrate that presence of either Qwave and or fQRS complexes on a 12-lead ECG in patients with suspected cardiac involvement of sarcoidosis may indicate the presence of greater infiltrative myocardial disease by cardiac magnetic resonance imaging. Fragmented QRS complexes (fQRS) on 12-lead ECG are a marker of greater myocardial scarring and were observed in some sarcoid patients (pts).

Inflammatory aortitis with coronary arterial involvement by multidetector cardiac computed tomography

A 40-year-old man with a history of hypertension was admitted for a non-ST-segment myocardial infarction. A multidetector coronary computed tomography (MDCCT) showed proximal aortic intramural thickening with extrinsic thickening and luminal compression of the proximal left circumflex coronary artery. Subsequent surgical evaluation and positron emission tomography imaging showed evidence of active inflammation of the proximal aorta and coronary arteries. Hence, this case illustrates an uncommon cause of myocardial ischemia and the emerging complimentary role that MDCCT can play in such patients.