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New-onset atrial fibrillation (NOAF) during acute myocardial infarction (AMI) has significant consequences but is often misdiagnosed. The aim of the study was to evaluate predictors of NOAF throughout different phases of AMI. Patients with AMI admitted to a tertiary medical center were analyzed. Exclusion criteria were preexisting AF, AMI onset ≥24 hours prior to admission, in-hospital death, significant valvular disease, and in-hospital coronary artery bypass graft. Study population were AMI without-NOAF, early-AF (AF terminated within 24 hours of admission), and late-AF (beyond the first 24 hours). Overall 5946 patients were included, age: 64.8 ±14.8 years; 30% women. The incidence of NOAF was 4.6%: 1.6% early-AF, and 3% late-AF. Patients with NOAF comprised greater rate of women, cardiovascular risk-factors burden, severe left ventricular-dysfunction, pulmonary hypertension, valvular disorders, and left atrial enlargement compared with patients without-NOAF. Non-ST-elevation myocardial infarction and inferior-ST-elevation myocardial infarction (STEMI) were significantly more prevalent among early-AF group, while anterior-STEMI, in late-AF. The final multivariate models showed c-statistics of 0.73 and 0.76 for the prediction of new-onset early-AF and late-AF, respectively. In conclusion, there are different clinical predictors of early- versus late-NOAF. The study points out "high risk" AMI population for more meticulous heart rate monitoring for NOAF. [ABSTRACT FROM AUTHOR]

Cardiovascular (CV) patients are becoming older with a greater number of CV risk factors (CVRFs). The Framingham risk score (FRS) includes the major CVRFs and is used for CV risk stratification. We investigated temporal trends in burden of CVRFs among patients with acute myocardial infarction (AMI) throughout a decade. Patients with AMI hospitalized through 2002 to 2012 were studied. The baseline characteristics included age, sex, ethnicity, type of AMI (ST-segment elevation [STEMI] vs non-STEMI [NSTEMI]), coronary artery disease (CAD), diabetes mellitus (DM), dyslipidemia, hypertension, obesity, smoking, and blood lipid profile. The FRS was calculated for each patient. A total of 14 698 AMI admissions were included (age 66.9 ± 13.6 years, 68% males, 47.6% STEMI). Half of admitted cases had ≥4 CVRFs. The mean FRS was 17.1 ± 4.1. Throughout the study period, patients with AMI became older with increased burden of CVRFs. The mean FRS increased from 16.8 ± 4.0 (2002) to 17.3 ± 4.1 (2012; P <.001). Multivariate analysis demonstrated a significant increase in FRS among patients with NSTEMI and significant decrease for patients with STEMI. Conclusions: The last decade, patients with AMI became older with increased burden of CVRFs. Framingham risk score increased among patients with NSTEMI and decreased in patients with STEMI. These trends impact on risk stratification and secondary prevention programs. [ABSTRACT FROM AUTHOR]

Potassium levels (K, mEq/L) fluctuate in patients with acute myocardial infarction (AMI). Potassium was reported to be associated with prognosis in patients with AMI; however, studies evaluating the prognostic value of K fluctuations in this setting are scarce. We retrospectively analyzed patients with AMI hospitalized in a tertiary medical center, through 2002 to 2012. Patients on chronic dialysis or mechanical ventilation were excluded. Based on all K values during hospitalization, minimal, maximal, and fluctuation (gap between 2 consecutive K) were recorded. Primary outcome was inhospital all-cause mortality. Overall, 10 032 patients were studied (age 68.1+14.3 years, 65.4% males, 44.2% ST-segment elevation MI), of which 507 (3.7%) died in hospital. Potassium decreased during the first 2 to 3 days (P for trend <.001), followed by stabilization (P for trend = .807). Potassium in the extreme categories (<3.8 and >4.7) and absolute fluctuations >0.1 mEq/L were more common among nonsurvivors than survivors (P < .001 each). In a multivariate analysis, combinations of minimal K <3.8 with maximal K > 4.7 (odds ratio [OR] = 18.1), K > 4.4 with fluctuation >0.1 (OR = 1.74), or <0.1 (OR = 2.6) and minimal K after the first 2 admission days (OR = 2.07) were associated with increased risk of mortality (P < .001 each). Potassium fluctuations, peak and nadir K, and its timing independently predict inhospital mortality in patients with AMI. [ABSTRACT FROM AUTHOR]

The author reflects on location of body potassium (K) in intracellular space with regulation of extracellular potassium by intracellular shifts and renal excretion. Topics discussed include modifications in electrophysiological property of resting membrane is done through changes in extracellular K levels, less occurrence of hypokalemia in isolated rabbit hearts than threshold of fibrillation and connection between hypokalemia and risk of ventricular arrhythmias in patients.

In this article, the authors talks about the European Society of Cardiology guidelines which includes new-onset atrial fibrillation (NOAF); and potentially important parameters to be obtained, analyzed as potential predictors and compared between the 2 subgroups of NOAF.