SSS was found to be associated with aging (mean age of 68 years old) due to age-related degenerative fibrosis of the SA node
The electrical impulses are generated by a cluster of cells in the right atrium that form the sinoatrial node, or SA node
. The SA node
acts as the heart's natural "pacemaker," sending electrical signals that produce a synchronized, steady heart rhythm.
The sinoatrial nodal artery is anatomically significant, because it is the landmark for the identification of the sinoatrial node (SA node
), which is the natural pacemaker of heart.
They do this by affecting the SA node
, the heart's natural pacemaker.
Out of the 35(32.7%) patients with syncope, 13(37%) had positive Holter findings including monomorphic PVC's 6(17%), wandering pacemaker 4(11.4 %), atrial ectopic beats 1(2.8%), sustained run of SVT 1(2.8%) and ectopic SA node
Syncope may occur with a rapid supraventricular tachycardia or ventricular tachycardia, usually as a result of a fall in cardiac output, or it may occur after termination of the tachycardia because of overdrive suppression of the SA node
Constant P-to-P intervals are an important characteristic of all types of second-degree heart block and result from the impulse originating in the SA node
. If a P-wave before a missing QRS is early (P-to-P interval not constant), a non-conducted premature atrial complex (PAC) would be indicated--a more benign finding (Surawicz & Knilans, 2008).
where [alpha] is the confidence, which denotes the probability that SA node
The electrical signals originating from the pace maker of the heart, SA node
, governs the heart rate, i.e.
The SA node
releases an impulse of depolarization (electricity) that is conducted through both the right and left atrium, causing them to contract.
First-degree SA nodal block is due to prolongation of conduction time between the SA node
impulse and depolarization of the rest of the RA (designated by the P wave on ECG).