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Background-The objective of this study was to develop an acute experimental model showing both focal and macroreentrant sustained atrial fibrillation (AF). Methods and Results-In 31 anesthetized dogs, bilateral thoracotomies allowed the attachment of electrode catheters at the right and left superior pulmonary veins, atrial free walls, and atrial appendages. Acetylcholine, 100 mmol/L, was applied topically to either appendage. Sequential radiofrequency ablation was achieved for the ganglionated plexi (GP), found adjacent to the 4 pulmonary veins. In 12 separate studies, a propafenone bolus, 2 mg/kg, was given before and after GP ablations at the start of acetylcholine-induced AF. Acetylcholine caused abrupt onset of AF (nϭ22) or induced AF by burst pacing (nϭ9) that lasted Ն10 minutes. Rapid, regular, or fractionated atrial electrograms were consistently seen (average cycle length, 37Ϯ7 ms) at the appendages versus cycle lengths of 114Ϯ23 ms at other atrial sites. After ablations of GP, AF abruptly terminated (nϭ25). In 6 dogs, sustained atrial tachyarrhythmias continued. Pacing at specific atrial sites organized electrograms of one atrium or also captured the other atrium. The latter resulted in termination when pacing was stopped in 4 of these 6 experiments. Propafenone did not change the duration of focal AF before GP ablation (17Ϯ9 versus 14Ϯ8 minutes; control, Pϭ0.6) but terminated reentrant atrial tachyarrhythmias (12Ϯ3 versus 2Ϯ1 minutes, Pϭ0.0009). Conclusions-Before GP ablation, acetylcholine (100 mmol/L) induced sustained AF characterized by rapid, focal firing.GP ablations were associated with loss of focal firing and regularization of electrograms in both atria before termination. Propafenone failed to terminate focal AF but rapidly terminated entrainable macroreentrant atrial tachyarrhythmias. (Circ Arrhythmia Electrophysiol. 2009;2:384-392.)

Preclinical studies demonstrate that generalized endothelial cell dysfunction and microvascular impairment are potentially reversible causes of age-related vascular cognitive impairment and dementia (VCID). The present study was designed to test the hypothesis that severity of age-related macro-and microvascular dysfunction measured in the peripheral circulation is an independent predictor of cognitive performance in older adults. In this study, we enrolled 63 healthy individuals into young (< 45 years old) and aged (> 65 years old) groups. We used principal component analysis (PCA) to construct a comprehensive peripheral vascular health

Isolation of the focal AF at the AA (primary trigger) by clamping caused cessation of activity in the AA, but AF continued due to secondary triggers arising from PVs. The possible mechanism(s) responsible for these findings are discussed, and various ancillary experiments (n = 28) were added to help elucidate mechanisms.

DES appear to reduce the incidence of ISR in CAV as compared with BMS. Prospective randomized clinical trials are needed to determine the clinical benefit of DES beyond a reduction in ISR.

Vasospastic angina is a diagnosis of exclusion that manifests with signs and symptoms, which overlap with obstructive coronary artery disease, most often ST-segment elevation myocardial infarction. The pharmacotherapy that is available to treat vasospastic angina can help ameliorate angina symptoms. However, the etiology of vasospastic angina is ill-defined, making targeted pharmacotherapy difficult. Most patients receive pharmacotherapy that includes calcium channel blockers and/or long-acting nitrates. This article reviews the efficacy and safety of the pharmacotherapy used to treat vasospastic angina. High-dose calcium channel blockers possess the most evidence, with respect to decreasing angina incidence, frequency, and duration. However, not all patients respond to calcium channel blockers. Nitrates and/or alpha1-adrenergic receptor antagonists can be used in patients who respond poorly to calcium channel blockers. Albeit, evidence for use of nitrates and alpha1-adrenergic receptor antagonists in vasospastic angina is not as robust as calcium channel blockers and can exacerbate adverse effects when added to calcium channel blocker therapy. Despite having a clear benefit in patients with obstructive coronary artery disease, the benefit of beta-adrenergic receptor antagonists, statins, and aspirin remains unclear. More data are needed to elucidate whether or not these agents are beneficial or harmful to patients being treated for vasospastic angina. Overall, the use of pharmacotherapy for the treatment of vasospastic angina should be guided by patient-specific factors, such as tolerability, adverse effects, drug-drug, and drug-disease interactions.

Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure. It is defined as cardiomyopathy that develops in the last month of pregnancy or within 5 months of the postpartum period without an identifiable cause. We conducted a systematic review of literature of prospective studies with a focus on echocardiographic and long-term clinical outcomes in PPCM. We searched MEDLINE and Embase up to October 1, 2017. Prospective studies (sample size ≥20) reporting all-cause mortality and follow-up duration of ≥1 year were included. Of the 956 studies identified, 7 met the inclusion criteria. A total of 445 patients with a mean age of 30 years (range, 27-32 years) were included. The mean follow-up duration was 41 months (range, 12-61 months). The majority of patients had New York Heart Association class III or IV symptoms at the time of diagnosis. Only 3 studies reported data on ethnicity where the majority of patients were non-Caucasian. Most of the patients (81%-93%) were on guideline-directed medical therapy, except 1 study (41%). Left ventricular ejection fraction at baseline ranged from 24% to 35% (mean, 28%) and at follow-up from 31% to 53% (mean, 44%). Recovery in systolic function was noted in 20% to 82% (mean, 50%) of patients. All-cause mortality ranged from 0% to 28% (mean, 16%). This systematic review summarizes the evidence to date on the clinical characteristics and outcomes of patients with PPCM. Multicenter registries with long-term follow-up will help shed further light on characteristics and outcomes of patients with this rare disease.