Robert F. Percy

Usefulness of Automated Serial 12-Lead ECG Monitoring During the Initial Emergency Department Evaluation of Patients With Chest Pain☆☆☆★

STUDY OBJECTIVE To determine whether the use of automated serial 12-lead ECG monitoring (SECG) is more sensitive and specific than the initial 12-lead ECG in the detection of injury and ischemia in patients with acute coronary syndromes (ACS) during the initial ED evaluation of patients with chest pain. METHODS A prospective observational study was performed in 1,000 patients with chest pain who were admitted to a university teaching hospital and who underwent continuous ST-segment monitoring with SECG during the initial ED evaluation. The initial ECG was obtained on presentation, and SECG readings were obtained at least every 20 minutes during the ED evaluation. Diagnostic abnormalities on the initial ECG were defined as injury or ischemia. Diagnostic changes on SECG were defined as evolving injury, evolving ischemia, new injury, or new ischemia. ACS was defined as acute myocardial infarction (AMI), recent myocardial infarction or unstable angina. RESULTS A diagnostic SECG was more sensitive than a diagnostic initial ECG for detection of AMI (68.1% versus 55.4%; P < .0001) and ACS (34.2% versus 27.5%; P < .0001). A diagnostic SECG was more specific than a diagnostic initial ECG for detection of ACS (99.4% versus 97.1%; P < .01). SECG detected injury in an additional 16.2% of AMI patients compared with the initial ECG (61.8% versus 45.6%; P < .0001; 95% confidence interval for difference of proportions, 10.9% to 21.4%). CONCLUSION SECG during the initial ED evaluation is more sensitive and more specific than the initial ECG in the identification of ACS. Patients with a diagnostic SECG need intensive antiischemic therapy, evaluation for reperfusion therapy, and admission to an ICU.

Initial ECG in Q wave and non-Q wave myocardial infarction.

The initial ECGs in 440 patients admitted for suspected acute myocardial infarction were retrospectively analyzed to determine predictive values of these ECGs for acute myocardial infarction and to determine differences in the initial ECG for Q wave and non-Q wave myocardial infarction. One hundred (23%) of the study patients were diagnosed as having an acute myocardial infarction. Acute injury was seen in 47% of these patients (positive predictive value [PPV], 84%; 95% confidence interval [CI], 72% to 92%), ischemia in 15% (PPV, 39%; 95% CI, 24% to 57%), and left ventricular hypertrophy with strain in 11% (PPV, 19%; 95% CI, 4% to 29%). Forty-three patients were diagnosed as having a Q wave infarction and 50 patients as having a non-Q wave infarction. Seventy-two percent of the patients with a Q wave infarction had acute injury as the initial ECG interpretation compared with 38% in the non-Q wave infarction group (P less than .001). In contrast, only 17% of patients with Q wave infarction had an initial ECG interpretation of ischemia or strain as compared with 36% of patients with non-Q wave infarction (P = .03). Because of the relatively high incidence of acute myocardial infarction in patients admitted with an initial ECG interpretation of ischemia or left ventricular hypertrophy with strain, prospective studies must be performed to determine if selective patients with acute ST segment depression or ischemic T wave inversion in the setting of suspected acute myocardial infarction may benefit from early thrombolytic therapy.

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: A systematic review and meta-analysis ☆

BACKGROUND The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification. METHODS We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index. RESULTS We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events. CONCLUSIONS Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

Correlation of paradoxical atrial septal motion and an interatrial pressure gradient in severe tricuspid regurgitation

Abstract The anatomic and hemodynamic sequelae of tricuspid regurgitation (TR) have been evaluated by M-mode and 2-dimensional (2-D) echocardiography. 1 Tei et al 2 observed abnormal (paradoxical) motion of the atrial septum toward the left atrium during systole on 2-D and M-mode echocardiograms. 2 These investigators postulated that the paradoxical motion of the atrial septum was a result of the TR-induced volume overload of the right atrium and an abnormal right atrial-left atrial (RA-LA) pressure gradient. However, Lin et al, 3 in a study of atrial septal motion in LA and RA volume overload states, contended that normal and abnormal atrial septal motion can be explained wholly by LA volume change. The patient described herein, who had severe TR and paradoxical motion of the atrial septum, documents an RA-LA pressure gradient and compares this gradient with RA-LA area changes (reflecting volume changes) during the cardiac cycle.

Prognostic Significance of Troponin T Elevation in Patients Without Chest Pain

Increased cardiac troponin with chest pain is important for the diagnosis, triage, and treatment of patients in the emergency department. However, the use of troponin for the diagnosis and triage of patients without chest pain is poorly established. The aim of this study was to determine 30-day and 1-year mortality and morbidity of troponin T increases in patients without chest pain. This retrospective study compared 92 hospitalized patients without (study group) and 91 patients with chest pain (control group), followed up for 1 year. Study group patients had troponin T >0.04 microg/L, normal creatine kinase or creatine kinase-MB fraction <5%, and no electrocardiographic ischemia. Excluded were high-risk patients with end-stage kidney disease, those with left ventricular ejection fraction <40%, and the critically ill. Outcome variables included 30-day and 1-year death, myocardial infarction, unstable angina, and coronary revascularization rates. Thirty-day (13.0% vs 4.4%; p = 0.032) and 1-year (33% vs 4.6%; p <0.001) mortality rates were significantly higher in the study group, whereas myocardial infarction, unstable angina, and revascularization were infrequent. In conclusion, patients with increased troponin T and no chest pain had a high mortality rate and required careful follow-up.

An algorithm for identification of ST-elevation myocardial infarction patients by emergency medicine services

OBJECTIVE ST-elevation myocardial infarction (STEMI) identification by emergency medicine services (EMS) leading to pre-hospital catheterization laboratory (CL) activation shortens ischemic time and improves outcomes. We examined the incremental value of addition of a screening clinical tool (CT), containing clinical information and a Zoll electrocardiogram (ECG)-resident STEMI identification program (ZI) to ZI alone. METHODS All EMS-performed and ZI-analyzed ECGs transmitted to a percutaneous coronary intervention hospital from October 2009 to January 2011 were reviewed for diagnostic accuracy. ZI performance was also compared to ECG interpretations by 2 experienced readers The CT was then retrospectively applied to determine the incremental benefit above the ZI alone. RESULTS ST-elevation myocardial infarction was confirmed in 23 (7.5%) of 305 patients. ZI was positive in 37 (12.1%): sensitivity: 95.6% and specificity: 94.6%, positive predictive value (PPV), 59.5%, negative predictive value (NPV), 99.6%, and accuracy of 93.8%. Moderate agreement was observed among the readers and ZI. CT criteria for CL activation were met in 24 (7.8%): 20 (83.3%) were confirmed STEMIs: sensitivity: 86.9%, specificity: 98.5%, a PPV: 83.3%, and NPV: 98.6%, accuracy of 97.7%. CT + ZI increased PPV (P<0.05) and specificity (P<0.003) by reducing false positive STEMI identifications from 15 (4.9%) to 4 (1.3%). CONCLUSIONS In an urban cohort of all EMS transmitted ECGs, ZI has high sensitivity and specificity for STEMI identification. Whereas the PPV was low, reflecting both low STEMI prevalence and presence of STEMI-mimics, the NPV was very high. These findings suggest that a simplified CT combined with computer STEMI interpretation can identify patients for pre-hospital CL activation. Confirmation of these results could improve the design of STEMI care systems.

Antemortem echocardiographic identification of right atrial thromboembolus.

1. Mintz GS, Kotler MN, Segal BL, Parry WR: Comparison of two-dimensional and M-mode echocardiography in the evaluation of patients with infective endocarditis. Am J Cardiol 43:738, 1979. 2. Stafford A, Wann LS, Dillon JC, Weyman AC, Feigenbaum H: Serial echocardiographic appearance of healing bacterial vegetations. Am J Cardiol 44:754, 1979. 3. Wann LS, Hallman CC, Dillon JC, Weyman AE, Feigenbaum H: Comparison of M-mode and cross-sectional echocardiography in infective endocarditis. Circulation 60:728, 1979. 4. Wann LS, Gross CM: Use of echocardiography in infective endocarditis. J Cardiovasc Ultrasonogr 1:381, 1982. 5. Sahn DJ, Allen HD: Real-time cross-sectional echocardioFebruary, 1985