A QS pattern in leads V1 and V2 is associated with septal scarring independent of scar etiology - A cardiac magnetic resonance imaging study.

BACKGROUND: Isolated septal myocardial infarction (MI) is traditionally characterized by the presence of pathological Q waves in leads V1 and V2 on the surface electrocardiogram (ECG). The purpose of this study was to determine the relation between this ECG pattern and septal scar on cardiac magnetic resonance (CMR) imaging. METHODS: We retrospectively reviewed the medical records of 996 consecutive patients who received both ECG and CMR. RESULTS: Nineteen patients had a Q wave in leads V1 and V2. Septal scar was present in all 19 patients. Based on CMR imaging criteria, septal scars were ischemic in 8 patients (42%) and non-ischemic in 11 patients (58%). CONCLUSION: The results suggest that the presence of a QS pattern in leads V1 and V2 on the surface ECG is highly predictive of the presence of a septal myocardial scar, but is not diagnostic for septal MI, even after excluding comorbidities known to produce a pseudo-septal MI pattern.

Left arm/left leg lead reversals at the cable junction box: A cause for an epidemic of errors.

Medical errors, especially due to misinterpretation of electrocardiograms (ECG), are extremely common in patients admitted to the hospital and significantly account for increased morbidity, mortality and health care costs in the United States. Inaccurate performance of an ECG can lead to invalid interpretation and in turn may lead to costly cardiovascular evaluation. We report a retrospective series of 58 sequential cases of ECG limb lead reversals in the ER due to inadvertent interchange in the lead cables at the point where they insert into the cable junction box of one ECG machine. This case series highlights recognition of ECG lead reversal originating in the ECG machine itself. This case series also demonstrates an ongoing need for education regarding standardization of ECG testing and for recognizing technical anomalies to deliver appropriate care for the patient.

High prevalence of iatrogenic hyperthyroidism in elderly patients with atrial fibrillation in an anticoagulation clinic.

In elderly patients with established atrial fibrillation (AF) who are receiving thyroid replacement, regular testing for thyroid function is often not performed, placing the patient at risk for iatrogenic hyperthyroidism. Of 215 patients followed in an anticoagulation clinic, 41 were receiving thyroid replacement and 15 of these were found to have hyperthyroidism. Eight had documented AF coincident with abnormal thyroid function. In addition, only 22 patients on thyroid replacement had an annual TSH. In conclusion, iatrogenic hyperthyroidism may frequently be missed in AF patients because of inadequate monitoring of serum TSH. Thyroid replacement is common in elderly patients with AF followed in an anticoagulation clinic. Laboratory evidence of hyperthyroidism occurred in 37%, usually in patients with higher doses of thyroid replacement, and often associated with AF. The frequency of iatrogenic hyperthyroidism may be underestimated in patients with AF since many patients who receive thyroid replacement therapy are not monitored regularly with serum TSH.

Management of premature ventricular complexes.

Premature ventricular contractions (PVCs) are frequently encountered, and management is determined by symptoms, precipitating factors, and the presence of underlying cardiac disease. No treatment is indicated in patients with asymptomatic PVCs in absence of cardiac disease. Symptomatic patients without cardiac disease may be managed by identifying and correcting reversible causes. In patients with cardiac disease, management includes treating the underlying cardiac disease to improve both symptoms and prognosis.

Outcomes and Hospital Utilization in Patients With Papillary Muscle Rupture Associated With Acute Myocardial Infarction.

Papillary muscles rupture (PMR) is a rare complication of acute myocardial infarction (MI) that can lead to severe hemodynamic compromise, acute heart failure, and death. This study was designed to assess demographics, outcomes, and hospital utilization trends in the management of PMR associated with acute MI. Data were derived from the National Inpatient Sample for the years 2005 to 2014. ICD-9 codes 410.0 to 410.9 were used to identify patients with acute MI. ICD-9 code 429.6 was used to identify patients with PMR. ICD-9 procedures codes 35.23, 35.24, and 35.12 were used to identify patients who underwent mitral valve replacement (MVR) or repair. Of the 3,244,799 admissions, 932 were complicated by PMR (incidence of 0.029%). The majority of patients with PMR were ≥65 years old (60.1%) and male (60.4%). Of those with PMR, 57.5% underwent MVR. Compared to patients without PMR, those with PMR had a significantly higher in-hospital mortality rate (5.3 vs 36.3%, p <0.001), cost of hospitalization ($20,205 vs $74,383, p <0.001) and length of hospital stay (4.67 ± 02 vs 11.2 ± 0.80 days, p <0.001). Predictors of in-hospital mortality in PMR patients were age, inferior wall acute MI, and cardiac arrest. Predictors of MVR in PMR patients were age, female gender, concomitant coronary artery bypass grafting, mechanical circulatory support, longer length of stay, and admission to a large hospital. In conclusion, patients with PMR associated with acute MI have higher risk of in-hospital mortality, greater cost of hospitalization and longer length of stay than patients acute MI without PMR.

Current perspectives of electrical remodeling and its therapeutic implications.

Electrical remodeling involves alterations in the electrophysiologic milieu of myocardium in various disease states, such as ventricular hypertrophy, heart failure, atrial tachyarrhythmias, myocardial ischemia, and infarction that are associated with cardiac arrhythmias. Although research in this area dates back to early part of the 19th century, we still lack the exact knowledge of ionic remodeling, the role of various genes and channel proteins, and their relevance for the newer antiarrhythmic therapies. Structural remodeling may also have an impact on the electrical remodeling process, although differences in both structural and electrical remodeling are associated with different disease states. Various electrophysiologic, cellular, and structural alterations, including anisotropic conduction, increased intracellular calcium levels, and gap junction remodeling predispose to increased dispersion of action potential duration and refractoriness. This constitutes a favorable substrate for early and late afterdepolarizations and reentrant arrhythmias. Studying the role of ionic remodeling in the initiation and propagation of cardiac arrhythmias has significant relevance for developing newer antiarrhythmic therapies, for identifying patients at risk of developing fatal arrhythmias, and for implementing effective preventive measures. Further research is required to understand the specific effects of individual ion channel remodeling, to understand the signal transduction mechanisms, and to address whether detrimental effects of electrical remodeling can be altered.