Chronic sinoatrial disorder (sick sinus syndrome): a possible result of cardiac ischaemia.

Abstract

Postmortem angiography was used to examine the blood vessels supplying the sinoatrial node in 25 subjects with chronic sinoatrial disorder (group 1). The results were compared with similar studies in 54 subjects who died of heart block and in whom sinus node function was normal (group 2). Although no significant lesion obstructing the blood flow to the sinus node was seen in the majority of those in group 1, there were abnormalities in seven cases, with reduced filling of the sinus node artery in five. In group 2 the sinus node artery filled normally in all cases despite major disease of the parent vessel in three. The combination of contralateral coronary artery disease with extensive atrial anastomoses was actively sought because this arrangement might predispose to a steal phenomenon. Such conditions were fully met in three cases in group 1 and two cases in group 2, and were found to a lesser extent in a further two cases in group 1 and three in group 2. Although coronary artery disease was unlikely to be the principal cause of sinus node dysfunction in most of the cases studied it was relatively common and may have been a factor in about one third. Improved survival after myocardial infarction may increase the number of patients with chronic sinoatrial disorder of ischaemic origin.

The Evaluation and Management of Bradycardia

“…28 Sinus-node dysfunction may be due to intrinsic pathologic characteristics of the sinus node itself, or it may be due to extrinsic causes (Table 1). [29][30][31][32][33] Intrinsic disease is characterized by the replacement of nodal tissue with fibrous tissue. Since the sinus node is a complex of cells in the atrial wall, permanent injury by infarction or infection is uncommon.…”

Fibrosis, Electrics and Genetics

“…40, 46 However, postmortem angiography has significant limitations and when the nodal artery was assessed in vivo it was seldom diseased (9%) in patients presenting with significant bradycardia. 47 Two small studies have assessed the prevalence of SAN artery disease in a group of patients with SND and clinical evidence of CAD (angina, prior inferior myocardial infarction or positive stress test).…”

The Incidence of Coronary Artery Disease in Patients with Symptomatic Bradyarrhythmias.

“…However, in the previous reports, a small portion of these patients had coexistent coronary artery disease (CAD). [1][2][3] The presence of CAD among patients with symptomatic bradyarrhythmia has several important clinical implications. First of all, CAD is a possible cause of these patients' dysrhythmia.…”

“…According to the previous reports, one-third of patients with sick sinus syndrome and 15% of patients with chronic atrioventricular block could be attributed to the underlying CAD. 2,3) Second, coexistent CAD is a major prognostic determinant in these patients. [6][7][8] Though most patients had major improvement of their clinical symptoms after pacemaker implantation, those with coexistent CAD had worse prognosis in the long-term follow up.…”