Abstract 9185: Diagnostic Utility of R-R Interval Variations Under Deep Breathing Load in Patients With Cardiac Amyloidosis

• Published in: Circulation (New York, N.Y.) Vol. 144; no. Suppl_1; p. A9185
• Main Authors: Nagayoshi, Yasuhiro, Kawano, Hiroaki, Sakaino, Naritsugu, Nishihara, Taiki, Morikawa, Kei, Hanatani, Shinsuke, Usuku, Hiroki, Tsujita, Kenichi
• Format: Journal Article
• Language: English
• Published: Lippincott Williams & Wilkins 16.11.2021
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.144.suppl_1.9185

IntroductionAutonomic disorder is one of important characteristics of cardiac amyloidosis. However, the prevalence of autonomic disorder in wild-type transthyretin amyloidosis (ATTRwt) remains to be elucidated. Analysis of coefficient of variation of R-R interval (CVR-R) is a non-invasive method to measure the autonomic nervous system. In normal subjects, CVR-R values are higher during deep breathing load than those at rest. Diminished response of CVR-R to deep breathing reflects the parasympathetic nervous system disorder. We aimed to assess autonomic disorder of ATTRwt and investigate the utility of CVR-R for the detection of ATTRwt from other cardiac disease. MethodsFifty patients with chronic heart failure (HF) patients aged >70 were investigated. The etiology of HF was as followsATTRwt, n=10; previous myocardial infarction (MI), n=20; and left ventricular hypertrophy (LVH) due to other disease (e.g. aortic stenosis); n=20. Serum cardiac troponin I and plasma brain natriuretic peptide (BNP) were measured in all patients. Cardiac function was evaluated by echocardiography. We measured CVR-R at rest (CVR-Rrest), CVR-R with deep breaths (CVR-Rbeath) and their change rate (CVR-Rdiff rate). Relative change formula is CVR-Rdiff rate = (CVR-Rbeath- CVR-Rrest)/ CVR-Rrest. ResultsThere was no difference in age among the three groups. Plasma BNP levels, troponin I levels and left ventricular mass index were significantly higher in ATTRwt group. There was no difference in CVR-Rrest levels among the three groups. CVR-Rdiff rate levels in ATTRwt group were significantly lower (ATTRwt-8.77 [-43.8-10.9]; LVH67.4 [38.7-89.4]; MI83.7 [60.4-142.9], respectively). In the ROC analysis to identify ATTRwt in HF, the best cutoff value for CVR-Rdiff rate was 1.197 (AUC0.848). ConclusionsAutonomic nervous disorder is frequently observed in the patients with ATTRwt. Measurement of CVR-R is convenient support tool for detection of ATTRwt.