Case Report Bradyarrhythmia

Recurrent Syncope





Persistent spontaneous sinus bradycardia not caused by drugs and inappropriate for the physiological circumstance


Sinus arrest or exit block,


Combinations of SA and AV conduction disturbances, or


Alternation of paroxysms of rapid regular or irregular atrial tachyarrhythmias and periods of slow atrial and ventricular rates (bradycardia-tachycardia syndrome)








Pathophysiology:


Grayanotoxins bind to sodium channels in cell membranes, preventing their inactivation and maintaining the cell in a state of depolarization, during which calcium entry might be facilitated.


More common among males, middle-aged. Male : Female ± 5:1


Toxic dose: 1 teaspoonful (15 g) of toxic honey


Heart rate and blood pressure returned to normal within 2 to 9 hrs treatment









Grayonotoxin


behaves like cholinergic agents


has dosage dependent adverse effects on the cardiovascular system


Metabolized and excreted within 24 hrs of intake.


Signs and symptoms: dizziness, fatigue, syncope, excessive perspiration, hypersalivation, nausea, vomiting, paresthesia, bradycardia, AVB, arterial hypotension, atrial fibrillation







AV block


Caused by conditions that can either decrease the rate of impulse conduction: ischemia, inflammation, compression, extreme stimulation of the heart by vagus nerve


Second degree AV block - Type 1 (aka Mobitz 1, Wenckebach): Progressive prolongation of PR interval with dropped beats (the PR interval gets longer and longer; finally one beat drops) . Type 2 (aka Mobitz 2, Hay): PR interval remains unchanged prior to the P wave which suddenly fails to conduct to the ventricles.


Third degree AV block - No association between P waves and QRS complexes


First degree AV block - PR interval greater than 0.20sec.
ECG:




SA node dysfunction


May be caused by extrinsic and intrinsic factors that decrease the automaticity or conduction of the SA node.


ECG: sinus bradycardia, sinus pauses, sinus arrest, sinus exit block, tachycardia, and chronotropic incompetence




Sick Sinus Syndrome





Problem #1 : Syncope


O2 2-4 liter/min per nasal canula


IVFD NaCl 0,09% 500cc/hour


Problem #2 : Bradyarrhythmia


Atropine sulfate 0,5 mg/IV


Serial ECG monitoring


Consider pacemaker implantation


Restriction from honey intake


Problem #4 : Hypokalemia


Correct hypokalemia with oral intake


Problem #3 : Hyperthyroidism


Refer to endocrinologist












Pathologic bradycardia


SA node dysfunction


AV conduction block


Physiologic bradycardia


(usually in young healthy athletes)


Bradycardia



















Plan
Hypokalemia
Clinical Features
Fatigue
Myalgia
muscular weakness of the lower extremities
bradycardia
may lead to progressive weakness
hypoventilation (d/t respiratory muscle involvement)
eventually complete paralysis

vary greatly depends on the degree of hypokalemia
Symptoms occur when K+