Emergent cardiac outcomes in patients with normal electrocardiograms in the emergency department.

BACKGROUND: Emergency physicians (EP) are frequently interrupted to screen electrocardiograms (ECG) from Emergency Department (ED) patients undergoing triage. Our objective was to identify discrepancies between the computer ECG interpretation and the cardiologist ECG interpretation and if any patients with normal ECGs underwent emergent cardiac intervention. We hypothesized that computer-interpreted normal ECGs do not require immediate review by an EP. METHODS: This was a retrospective study of adult (≥ 18 years old) ED patients with computer-interpreted normal ECGs. Laboratory, diagnostic testing and clinical outcomes were abstracted following accepted methodologic guidelines. The primary outcome was emergent cardiac catheterization (within four hours of ED arrival). All ECGs underwent final cardiologist interpretation. When cardiology interpretation differed from the computer (discrepant ECG interpretation), the difference was classified as potentially clinically significant or not clinically significant. Data was described with simple descriptive statistics. MAIN FINDINGS: 989 ECGs interpreted as normal by the computer were analyzed with a mean age of 50.4 ± 16.8 years (range 18-96 years) and 527 (53%) female. Discrepant ECG interpretations were identified in 184 cases including 124 (12.5%, 95% CI 10.4, 14.7%) not clinically significant and 60 (6.1%, 95% CI 4.6, 7.7%) potentially clinically significant. The 60 potentially clinically significant changes included: ST/T wave changes 45 (75%), T wave inversions 6 (10%), prolonged QT 3 (5%), and possible ischemia 10 (17%). Of these 60, 21 (35%) patients were admitted. Six patients had potassium levels >6.0 mEq/L, with one having a potentially clinically significant ECG change. No patient (0%, 95% CI 0, 0.3%) underwent immediate (within four hours) cardiac catherization whereas two underwent delayed cardiac interventions. CONCLUSIONS: Cardiologists frequently disagree with a computer-interpreted normal ECG. Patients with computer-interpreted normal ECGs, however, rarely had significant ischemic events. A rare number of patients will have important cardiac outcomes regardless of the computer-generated normal ECG interpretation. Immediate EP review of the ECG, however, would not have changed these patients' ED courses.

Cannabis use and acute coronary syndrome.

Introduction: Cannabis smoking can result in elevation of heart rate and blood pressure immediately after use, possibly from sympathetic nervous system stimulation and parasympathetic nervous system inhibition. Vascular inflammation, platelet activation, and carboxyhemoglobin generation have also been proposed as potential side effects of cannabis smoking. As such, an association between cannabis use and acute coronary syndrome has been postulated. Objective: The objective of our study was to analyze systematically the medical literature pertaining to this putative association. Methods: PubMed, Google Scholar, and OpenGrey were queried using a unique search string. All human trials, case series, or case reports of cannabis use and acute coronary syndrome in any language were considered in the literature search. The definition of acute coronary syndrome represented a penumbra that included chest pain, angina pectoris, unstable angina, myocardial infarction, myocardial ischemia, and cardiac arrest. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Our final search strategy included free-text words (TW): ("cannabis"[TW] OR "marijuana"[TW]) AND ("acute coronary syndrome"[TW] OR "myocardial" OR "ischemia"[TW] OR "infarction"[TW] OR "chest pain"[TW] OR "cardiac arrest"[TW] OR "angina"[TW]). To remain consistent over a span of five decades, we specifically did not include any publications with non-phytogenic, non-smoked cannabis as the sole etiology, as these are relatively recent and may possess additional pharmacologic characteristics compared to phytogenic cannabinoids. Therefore, for the purpose of this review, the term "cannabis" refers to the smoked phytogenic form. The search resulted in 325 articles. References in each selected publication were carefully hand-searched for any additional reports having relevance, and a total of 12 publications were identified in this manner. Following comparison and discussion amongst the co-authors, duplicate and non-relevant publications were removed, and a total of 85 publications involving 541,518 human subjects were selected for inclusion. Results were synthesized and reviewed by the authors for relevance. Clinical trials, observational studies, retrospective studies, case series, and case reports were graded using Oxford Centre for Evidence-based Medicine guidelines. Results: There were no Level I randomized blinded controlled studies specifically addressing the cannabis/acute coronary syndrome association. However, there were five Level I systematic reviews, 14 Level II studies with 83,961 subjects, and 14 Level III studies with 457,495 subjects. Conclusions from 28 of these 33 studies highlighted an increased risk of both acute coronary syndrome and chronic cardiovascular disease from cannabis use. The systematic reviews were wide-ranging in topic and scale, and none specifically focused on the association between cannabis use and acute coronary syndrome. The dissenting studies included two systematic reviews, one concluding there was limited and weak evidence for association of cardiovascular disease and acute coronary syndromes with cannabis use, and another citing the evidence was inconclusive. The other dissenting articles were two longitudinal prospective studies and a retrospective review concluding cannabis users had lower post-myocardial infarction mortality. There were 51 case series (Level IV) and case reports (Level V) with 62 subjects. Six cases were female (10%). Average age was 31 ± 12 years, reported maximum heart rate was 88 ± 21 bpm, systolic blood pressure was 125 ± 32 mmHg, and diastolic blood pressure was 80 ± 17 mmHg. ST-segment elevation was documented on 37 (60%) electrocardiograms, and the most common angiographic finding was left anterior descending coronary arterial occlusion and/or stenosis in 22 (35%) patients. Concomitant cardiomyopathy was described in 21 (34%) cases. There were 14 (23%) deaths attributed to acute coronary syndrome associated with cannabis use. Conclusion: There were five Level I systematic reviews, 14 Level II studies with 83,961 subjects, and 14 Level III studies with 457,495 subjects. All but five Level I-III publications highlighted an increased risk of both acute coronary syndrome and chronic cardiovascular disease associated with cannabis use.