Sick Sinus Syndrome, June 21, 1986

Sick Sinus Syndrome, June 21, 1986

About 50% of cases are caused by coronary heart disease or myocardial infarction, while the other half are idiopathic sick sinus syndrome with no obvious cause. However, pathological anatomy reveals fibrotic lesions around the sinoatrial node. Clinical manifestations include chest tightness, palpitations, dizziness, paroxysmal syncope, and bradycardia, sometimes with paroxysmal tachycardia—a condition known as tachy-brady syndrome—and occasionally sudden death. The electrocardiogram is the main diagnostic basis for this condition: ① sinus bradycardia; ② sinoatrial block; ③ sinus pause; ④ atrial and nodal escape beats; ⑤ atrial fibrillation; ⑥ paroxysmal supraventricular tachycardia. Among these ECG features, ①, ②, and ③ are basic lesions, ④ is a compensatory lesion, and ⑤ and ⑥ are lesions that cannot be compensated. Diagnosis of this condition includes: ① exercise test; ② atropine test; ③ isoproterenol test.