Postural orthostatic tachycardia syndrome: New concepts in pathophysiology and management.

Postural orthostatic tachycardia syndrome (POTS) is a common and therapeutically challenging condition affecting numerous people worldwide. Recent studies have begun to shed light on the pathophysiology of this disorder. At the same time, both non-pharmacologic and pharmacologic therapies have emerged that offer additional treatment options for those afflicted with this condition. This paper reviews new concepts in both the pathophysiology and management of POTS.

Drugs of Abuse and Heart Failure.

Substance use is common among those with heart failure (HF) and is associated with worse clinical outcomes. Alcohol, tobacco, cannabis, and cocaine are commonly abused substances that can contribute to the development and worsening of HF. Heavy alcohol consumption can lead to dilated cardiomyopathy, whereas moderate intake may decrease incident HF. Tobacco increases the risk of HF through coronary artery disease and coronary artery disease-independent mechanisms. Continued smoking worsens outcomes for those with HF and cessation is associated with an improved risk of major adverse cardiac events. Cannabis has complex interactions on the cardiovascular system depending on the method of consumption, amount consumed, and content of cannabinoids. Delta-9-tetrahydrocannabinol can increase sympathetic tone, cause vascular dysfunction, and may increase the risk of myocardial infarction. Cannabidiol is cardioprotective in preclinical studies and is a potential therapeutic target. Cocaine increases sympathetic tone and is a potent proarrhythmogenic agent. It increases the risk of myocardial infarction and can also lead to a dilated cardiomyopathy. The use of beta-blockers in those with HF and cocaine use is likely safe and effective. Future studies are needed to further elucidate the impact of these substances both on the development of HF and their effects on those who have HF.

Cerebral metastasis of Merkel cell carcinoma following resection with negative margins and adjuvant external beam radiation: a case report.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor of the skin. It is associated with advanced age, ultraviolet (UV) radiation, and Merkel cell polyomavirus. It has a predilection for the lymphatic system, but rarely spreads to the central nervous system. CASE PRESENTATION: A 71-year-old Caucasian man with a history of rheumatoid arthritis and MCC of the right lower eyelid and cheek presented with left-sided hemineglect and word-finding difficulty. Twenty months earlier he had undergone local excision of a 3 cm lesion with negative margins, negative sentinel lymph node biopsy, and external beam radiation. On presentation he was found to have a 6.3 cm mass in the right frontotemporal region. He underwent prompt resection, with pathological analysis consistent with metastatic MCC. He subsequently underwent stereotactic radiosurgery (SRS) and adjunctive immunotherapy with pembrolizumab. He has since tolerated the therapy well and is currently without neurological symptoms or evidence of recurrence. CONCLUSIONS: Cerebral metastasis of MCC is a rare event and should be considered when a patient with a history of MCC presents with neurological symptoms. Optimal treatment regimens of these rare cases are unclear; however, prompt resection, stereotactic radiosurgery, and adjunctive immunotherapy have shown an initial positive response in this patient.

Tobacco smoking in patients with heart failure and coronary artery disease: A 20-year experience at Duke University Medical Center.

Smoking is associated with incident heart failure (HF), yet limited data are available exploring the association between smoking status and long-term outcomes in HF with reduced vs. preserved ejection fraction (i.e., HFrEF vs. HFpEF). METHODS: We performed a retrospective analysis of HF patients undergoing coronary angiography from 1990-2010. Patients with coronary artery disease (CAD) and HF were stratified by EF (< 50% vs. ≥50%), smoking status (prior/current vs. never smoker), and level of smoking (light/moderate vs. heavy). Time-from-catheterization-to-event was examined using Cox proportional hazard modeling for all-cause mortality (ACM), ACM/myocardial infarction/stroke (MACE), and ACM/HF hospitalization with testing for interaction by HF-type (HFrEF vs. HFpEF). RESULTS: Of 14,406 patients with CAD and HF, 85% (n = 12,326) had HFrEF and 15% (n = 2080) had HFpEF. At catheterization, 61% of HFrEF and 57% of HFpEF patients had a smoking history. After adjustment, there was a significant interaction between HF-type and the association between smoking status and MACE (interaction P = .009). Smoking history was associated with increased risk for MACE in patients with HFrEF (adjusted hazard ratio [HR] 1.18 [1.12-1.24]), but not HFpEF (HR 1.01 [0.90-1.12]). Active smokers had increased mortality following adjustment compared to former smokers regardless of HF-type (HFrEF HR 1.19 [1.06-1.32], HFpEF HR 1.30 [1.02-1.64], interaction P = .50). Heavy smokers trended towards increased risk of adverse outcomes versus light/moderate smokers; these findings were consistent across HF-type (interaction P > .12). CONCLUSION: Smoking history was independently associated with worse outcomes in HFrEF but not HFpEF. Regardless of HF-type, current smokers had higher risk than former smokers.

Pacemaker and Defibrillator Implantation in Patients with Transposition of the Great Arteries.

Transposition of the great arteries (TGA) is represented in 5% to 7% of patients with congenital heart disease. These patients face a significant burden of arrhythmia and sudden cardiac death throughout their lives, and many eventually undergo pacemaker or cardiac-defibrillator implantation. Outcomes data following device implantation in this population, however, are limited. From an electrophysiologic database at a large, tertiary care medical center, we identified 63 TGA patients (34 with dextro (d)-TGA and 29 with levo (l)-TGA) with systemic right ventricles receiving an implantable cardiac device from 1996 to 2014. Medical records were reviewed for demographic, echocardiography and device interrogation data. Overall, l-TGA patients were older than d-TGA patients when they underwent initial device implantation (35.6 ± 18.2 versus 17.3 ± 10.6 years, p<0.001), and had more concomitant cardiac defects (55% versus 12%, p<0.001). Survival following initial device implantation was similar between l-TGA and d-TGA (72% versus 74%, p = 1.00), despite the baseline difference in age. Twenty-four patients underwent implantable cardioverter-defibrillator (ICD) implantation: 18 for primary intervention (11 l-TGA and seven d-TGA), and six for secondary prevention (four l-TGA and two d-TGA). Sixty-seven percent of patients in the secondary prevention group had appropriate shocks, compared with 0% of primary prevention patients. Patients with ICD discharge were more likely to have concomitant heart defects (100% versus 30%, p = 0.011). Despite being significantly younger, d-TGA patients had similar survival rates following device implant to l-TGA patients. Patients with TGA and sustained ventricular arrhythmias are at high risk for subsequent events, and typically benefit from ICD implantation. The role of prophylactic ICD implantation in this population, however, remains uncertain.