Case Report: Severe Peripartum Cardiac Disease in Myotonic Dystrophy Type 1.

Background: Myotonic dystrophy type 1 (DM1) is a hereditary muscular dystrophy affecting ∼2.1-14.3/100,000 adults. Cardiac manifestations of DM1 include conduction disorders and rarely cardiomyopathies. DM1 increases the risk of obstetric complications, however, little is known about the relationship between pregnancy and cardiomyopathy in DM1 due to disease rarity. Case: A 23-year-old with DM1 developed cardiomyopathy during pregnancy. Despite initial medical stabilization, she subsequently developed multiple spontaneous coronary artery dissections postpartum, worsening cardiomyopathy and multiorgan failure. She died 5 months postpartum. Conclusion: Though cardiomyopathy and arterial dissection are both known complications of pregnancy, this case suggests individuals with myotonic dystrophy type 1 may be at heightened risk for cardiac disease during the peripartum period. Physicians caring for women with suspected or proven DM1 should offer counseling and be alerted to the risk of cardiac complications with pregnancy and in the peripartum period. Pregnant and peripartum women with DM1 are likely to benefit from more frequent assessments of cardiac function including echocardiograms and early institution of heart failure management protocols when symptoms of cardiomyopathy present.

Suspicious index in Lyme carditis: Systematic review and proposed new risk score.

BACKGROUND: Lyme carditis (LC), an early manifestation of Lyme disease that most commonly presents as high-degree atrioventricular block (AVB), usually resolves with antibiotic treatment. When LC is not identified as the cause of AVB, a permanent pacemaker may be inappropriately implanted in a reversible cardiac conduction disorder. HYPOTHESIS: The likelihood that a patient's high-degree AVB is caused by LC can be evaluated by clinical characteristics incorporated into a risk stratification tool. METHODS: A systematic review of all published cases of LC with high-degree AVB, and five cases from the authors' experience, was conducted. The results informed the development of a new risk stratification tool, the Suspicious Index in LC (SILC) score. The SILC score was then applied to each case included in the review. RESULTS: Of the 88 cases included, 51 (58%) were high-risk, 31 (35.2%) intermediate-risk, and 6 (6.8%) low-risk for LC according to the SILC score (sensitivity 93.2%). For the subset of 32 cases that reported on all SILC variables, 24 (75%) cases were classified as high-risk, 8 (25%) intermediate-risk, and 0 low-risk (sensitivity 100%). Specificity could not be assessed (no control group). Notably, 6 of the 11 patients who received permanent pacemakers had reversal of AVB with antibiotic treatment. CONCLUSION: The SILC risk score and COSTAR mnemonic (constitutional symptoms; outdoor activity; sex = male; tick bite; age < 50; rash = erythema migrans) may help to identify LC in patients presenting with high-degree AVB, and ultimately, minimize the implantation of unnecessary permanent pacemakers.