Why do we keep missing left circumflex artery myocardial infarctions?

BACKGROUND: Diagnosis of left circumflex artery (LCx) myocardial infarctions via 12­lead electrocardiogram (ECG) has posed a challenge to healthcare professionals for many years. METHODS AND RESULTS: A retrospective observational study was performed to analyze patients admitted with myocardial infarction. The study used electronic medical records and specific ICD-10 codes to identify eligible patients, resulting in 2032 encounters. After independent adjudication of cardiac biomarkers, coronary angiography, and electrocardiographic changes, a final patient population of 58 encounters with acute occlusion myocardial infarction (OMI) with a culprit LCx lesion was established. OMI was defined as a lesion with either thrombolysis in myocardial infarction flow (TIMI) 0-2 or TIMI 3 with Troponin I > 1 ng/mL (Reference range 0.00-0.03 ng/mL). ECGs of these patients were then independently evaluated and grouped into 8 different classifications based on the presence or absence of ST elevation and/or depression in corresponding leads. ECG patterns and anatomical characteristics (proximal or distal to the first obtuse marginal artery) of the LCx lesions were then correlated. The appropriateness of triage and delay in reperfusion therapy were also assessed. Those with a left dominant or codominant circulation, and with LCx lesions proximal to the first obtuse marginal artery, were more likely to present with no or subtle ST-segment changes that led to delays in reperfusion therapy. CONCLUSIONS: Patients with left or codominant coronary artery circulation, with OMI proximal to the first obtuse marginal artery, may be less likely to have "classic" findings of ST-segment elevation on ECG due to cancellation forces in the limb leads.

Transient 2:1 Atrioventricular Block with Peri-Conduction System Pacing After Leadless Pacemaker Implantation.

This report discusses a case of transient 2:1 atrioventricular block with conduction system pacing 4 hours after leadless right ventricular pacemaker implantation in a 19-year-old patient with a history of cardioinhibitory syncope and asystole cardiac arrest but without preexisting atrioventricular block. The atrioventricular block was resolved spontaneously. Pacing morphology was suggestive of right bundle branch pacing. Neither 2:1 atrioventricular block nor conduction system pacing has previously been a reported outcome of right ventricular leadless pacemaker implantation. The report demonstrates that conduction system pacing with leadless devices is achievable. Further study of techniques, limitations, and complications related to intentional right ventricular leadless conduction system pacing is warranted.

Innovations in ventricular tachycardia ablation.

Catheter ablation of ventricular arrhythmias (VAs) has evolved significantly over the past decade and is currently a well-established therapeutic option. Technological advances and improved understanding of VA mechanisms have led to tremendous innovations in VA ablation. The purpose of this review article is to provide an overview of current innovations in VA ablation. Mapping techniques, such as ultra-high density mapping, isochronal late activation mapping, and ripple mapping, have provided improved arrhythmogenic substrate delineation and potential procedural success while limiting duration of ablation procedure and potential hemodynamic compromise. Besides, more advanced mapping and ablation techniques such as epicardial and intramyocardial ablation approaches have allowed operators to more precisely target arrhythmogenic substrate. Moreover, advances in alternate energy sources, such as electroporation, as well as stereotactic radiation therapy have been proposed to be effective and safe. New catheters, such as the lattice and the saline-enhanced radiofrequency catheters, have been designed to provide deeper and more durable tissue ablation lesions compared to conventional catheters. Contact force optimization and baseline impedance modulation are important tools to optimize VT radiofrequency ablation and improve procedural success. Furthermore, advances in cardiac imaging, specifically cardiac MRI, have great potential in identifying arrhythmogenic substrate and evaluating ablation success. Overall, VA ablation has undergone significant advances over the past years. Innovations in VA mapping techniques, alternate energy source, new catheters, and utilization of cardiac imaging have great potential to improve overall procedural safety, hemodynamic stability, and procedural success.

Relation of T Wave Positivity in Lead aVR to Ischemic Etiology of Cardiomyopathy.

Identifying ischemic etiology of cardiomyopathy carries prognostic and therapeutic significance. Clinical and electrocardiographic parameters can predict ischemic cardiomyopathy. Positive T wave polarity in lead aVR (TPaVR) has been associated with adverse cardiac events and severity of coronary artery disease. Medical records of adults evaluated in an advanced heart failure referral clinic for cardiomyopathy with systolic dysfunction (ejection fraction ≤ 40%) were retrospectively reviewed. Patients with ventricular pacing were excluded. Significant predictors of ischemic cardiomyopathy from a univariate logistic regression model were entered simultaneously into a multivariate logistic regression model. A total of 180 patients met study inclusion criteria. Mean age of the population was 52.5 ± 15.3 years old and 65% were men. Ischemic cardiomyopathy was present in 52 patients (29%). Positive TPaVR was present in 57 patients (32%). Ischemic cardiomyopathy was more common in patients with positive TPaVR (63% vs 13%, p < 0.001). Ischemic cardiomyopathy was independently predicted by male gender, diabetes, hyperlipidemia, absence of family history of cardiomyopathy, echocardiographic regional wall motion abnormality, and positive TPaVR. The strongest association was with positive TPaVR (odds ratio 30.5, 95% confidence interval 6.47 to 214; p < 0.001). T wave amplitude of +0.025 mV in lead aVR was the optimal cutoff to distinguish ischemic and nonischemic cardiomyopathy in receiver operating characteristic analysis (sensitivity 69.2%, specificity 83.6%, area under curve = 0.747, 95% confidence interval 0.658 to 0.836). In conclusion, positive TPaVR was a strong predictor of ischemic etiology of cardiomyopathy.

Challenges in the Provision of End-of-Life and Palliative Care to Ethnic Nepali Refugees.

After over a decade of resettlement of ethnic Nepali refugees in the U.S., a significant population of seriously ill refugees will require palliative care and hospice care. The refugee experience and culturally specific factors affect the end-of-life care of this population. Challenges in the end-of-life care of Nepali refugees include challenges related to social and health inequities, such as significant chronic respiratory disease burden; lack of protocols for deferral of illness disclosure; lack of support for group decision making; unfamiliarity with spiritual, religious, and traditional health practices; and difficulty with cross-cultural communication. Culturally competent care of ethnic Nepali refugees can be accomplished through respectful exploration of patients' and families' preferences regarding the challenges identified. This article presents recommendations that can guide primary and specialist palliative care for this population.

Early Detection of In-Patient Deterioration: One Prediction Model Does Not Fit All.

OBJECTIVES: Early detection of subacute potentially catastrophic illnesses using available data is a clinical imperative, and scores that report risk of imminent events in real time abound. Patients deteriorate for a variety of reasons, and it is unlikely that a single predictor such as an abnormal National Early Warning Score will detect all of them equally well. The objective of this study was to test the idea that the diversity of reasons for clinical deterioration leading to ICU transfer mandates multiple targeted predictive models. DESIGN: Individual chart review to determine the clinical reason for ICU transfer; determination of relative risks of individual vital signs, laboratory tests and cardiorespiratory monitoring measures for prediction of each clinical reason for ICU transfer; and logistic regression modeling for the outcome of ICU transfer for a specific clinical reason. SETTING: Cardiac medical-surgical ward; tertiary care academic hospital. PATIENTS: Eight-thousand one-hundred eleven adult patients, 457 of whom were transferred to an ICU for clinical deterioration. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We calculated the contributing relative risks of individual vital signs, laboratory tests and cardiorespiratory monitoring measures for prediction of each clinical reason for ICU transfer, and used logistic regression modeling to calculate receiver operating characteristic areas and relative risks for the outcome of ICU transfer for a specific clinical reason. The reasons for clinical deterioration leading to ICU transfer were varied, as were their predictors. For example, the three most common reasons-respiratory instability, infection and suspected sepsis, and heart failure requiring escalated therapy-had distinct signatures of illness. Statistical models trained to target-specific reasons for ICU transfer performed better than one model targeting combined events. CONCLUSIONS: A single predictive model for clinical deterioration does not perform as well as having multiple models trained for the individual specific clinical events leading to ICU transfer.

A Needs Assessment of Palliative Care Education among the United States Adult Neurology Residency Programs.

BACKGROUND: Palliative care (PC) needs in patients with neurological diseases are becoming more recognized by neurologists and PC physicians. OBJECTIVE: To qualify and quantify the PC education available in the United States adult neurology programs since the Accreditation Council for Graduate Medical Education (ACGME) published updated mandates in 2009. DESIGN: A 22-question survey was electronically distributed to each neurology residency program in the United States. SETTING/SUBJECTS: All program directors (PDs) and assistant/associate program directors (APDs) of adult neurology programs. RESULTS: This study had a 35% survey response rate (49 programs). Of the participating programs, 20% offer no PC education to residents. Communication, prognostication, and withdrawing life-prolonging therapies were the domains identified as the most important for resident education; these were also the domains PDs/APDs were most comfortable providing for their own patients, and the domains their residents are the best trained in currently. Addressing spiritual distress was the domain considered the least important, the domain PDs/APDs were least comfortable providing for their own patients, and the domains residents are currently the least well-trained in. Forty-two percent of programs were dissatisfied with the PC education available at their program. Time for teaching, availability of faculty, and faculty expertise were the most common barriers. CONCLUSIONS: PC education varies greatly across the United States adult neurology residency programs despite ACGME requirements. As time and resources limit current training, utilization of interdisciplinary educational teams and nationally available PC educational material may improve implementation of PC education in these residency programs.