Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels comprise a small
subfamily of proteins within the superfamily of pore-loop cation channels. In mammals, the …

Ion channels on the surface membrane of sinoatrial nodal pacemaker cells (SANCs) are the
proximal cause of an action potential. Each individual channel type has been thoroughly …

Protein kinase A (PKA) is a central regulator of cardiac performance and morphology.
Myocardial PKA activation is induced by a variety of hormones, neurotransmitters, and stress …

The heart automaticity is a fundamental physiological function in higher organisms. The
spontaneous activity is initiated by specialized populations of cardiac cells generating …

Optimal cardiac function depends on proper timing of excitation and contraction in various
regions of the heart, as well as on appropriate heart rate. This is accomplished via …

Electrogenesis in the heart begins in the sinoatrial node and proceeds down the conduction
system to originate the heartbeat. Conduction system disorders lead to slow heart rates that …

The heartbeat originates within the sinoatrial node (SAN), a small structure containing<
10,000 genuine pacemaker cells. If the SAN fails, the∼ 5 billion working cardiomyocytes …

artery (Figure 2B), although the relationship to the artery varies from individual to individual.
8 The nodal cells are set in a matrix of fibrous tissue, with a relatively discrete boundary …

The sinoatrial node is perhaps one of the most important tissues in the entire body: it is the
natural pacemaker of the heart, making it responsible for initiating each-and-every normal …

It is highly debated how cyclic adenosine monophosphate-dependent regulation (CDR) of
the major pacemaker channel HCN4 in the sinoatrial node (SAN) is involved in heart rate …