Adrenergic receptor polymorphisms in patients with stress (tako-tsubo) cardiomyopathy

Stress (tako-tsubo) cardiomyopathy (SC) is a newly reported condition afflicting older women, characterized by acute left ventricular (LV) systolic dysfunction, triggered by emotionally and physically stressful events, and occurring without significant coronary obstruction. Sympathetic nervous system hyperactivity has been implicated in the pathophysiology of SC. Single nucleotide polymorphisms involving the adrenergic receptors (AR) might result in susceptibility to SC.

Forty-one female SC patients were identified aged 34-89 years (mean 65) and were compared with 43 control females of similar age with respect to AR genotype frequencies for B1 receptor (amino acid positions 389 and 49) and alpha 2c receptor (deletion 322-325).

For SC patients, initial LV ejection fraction was 32 ± 10% vs. 62 ± 11% in control patients, p < 0.05. Genotype frequencies for SC patients vs. controls were B1 389 Arg/Arg (0.49 vs. 0.51), B1 389 Arg/Gly (0.49 vs. 0.49), B1 389 Gly/Gly (0.02 vs. 0), B1 49 Ser/Ser (0.88 vs. 0.81), B1 49 Ser/Gly (0.12 vs. 0.16), B1 49 Gly/Gly (0 vs. 0.02), alpha 2c Wt/Wt (0.93 vs. 0.86), and alpha 2c Wt/Del 322-325 (0.07 vs. 0.14); p = ns for all comparisons.

Genotype polymorphism frequencies for B1 receptor (amino acid positions 389 and 49) and alpha 2c receptor (deletion 322-325) are not significantly different in SC patients compared to female controls. These data suggest that these AR polymorphisms do not mediate the sympathetic nervous system hyperactivity in SC patients.