Upregulation of the Hyperpolarization-Activated Current Increases Pacemaker Activity of the Sinoatrial Node and Heart Rate During Pregnancy in Mice

• Published in: Circulation (New York, N.Y.) N.Y.), 2013-05, Vol.127 (20), p.2009-2020
• Main Authors: El Khoury, Nabil, Mathieu, Sophie, Marger, Laurine, Ross, Jenna, El Gebeily, Gracia, Ethier, Nathalie, Fiset, Céline
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cyclic Nucleotide-Gated Cation Channels - biosynthesis; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Female; Heart Conduction System - physiology; Heart Rate - physiology; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; Ion Channels - biosynthesis; Medical sciences; Mice; Potassium Channels; Pregnancy - physiology; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sinoatrial Node - physiology; Up-Regulation - physiology
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.113.001689

BACKGROUND—Pregnancy is associated with a faster heart rate (HR), which is a risk factor for arrhythmias. However, the underlying mechanisms for this increased HR are poorly understood. Therefore, this study was performed to gain mechanistic insight into the pregnancy-induced increase in HR. METHODS AND RESULTS—Using surface ECG we observed that pregnant (P) mice have faster HR (531±14 beats per minute [bpm]) compared with nonpregnant (NP) mice (470±27 bpm; P