Physiological Basis Of Arrrhythmias

Question 1

Sinus bradycardia causes and symptoms

Answer 1

Causes: trained athletes, during sleep, B blocking drugs, Coronary Artery Disease, Sick Sinus Syndrome

Symptoms: dizziness, syncope, fatigue and palpitations

Question 2

Paroxysmal tachycardia definition, result and cause

Answer 2

Abrupt rapid heartbeat with quick termination
Cause- ectopic foci; Reentry of impulse in atria or ischemic damage in ventricle
Result- rapid contraction; less ventricular filling

Question 3

Paroxysmal tachycardia I’m ventricle may be a precursor of what?

Answer 3

Ventricular fibrillation which results from digitalis toxicity (digoxin, digitoxin)

Question 4

Fibrillation definition

Answer 4

Arrhythmia leading to in effective pumping. Due to reentry of loop into multiple irregular circuits.

Question 5

Atrial fibrillation definition, heart rhythm, complication and treatment

Answer 5

Atria do not contract and relax sequentially
No p wave, reduction in ventricular pumping
Complication- embolism in left atria, stroke
Manifestation- affected by underlying disease, ventricular rate, heart function
Therapy- treat underlying disease,
drug therapy: digitalis, B blockers
Restore sinus rhythm: maze surgery, drug
Antithrombotic therapy- warafin, aspirine

Question 6

VF definition, cause, manifestation , treatment

Answer 6

Continuous twitching of the ventricle
No blood pumping
Loss of consciousness
Cause- premature impulse arriving during vulnerable phase
Treatment- Electric shock leaves ventricles temporarily refractory and allowing SA node to take over

Question 7

Hypernatremia

Answer 7

Inhibit Calcium entry, depresses overall activity of heart; negative inotropic effect

Question 8

Hypernatremia results in

Answer 8

Inhibit calcium entry, negative iontropy effect

Question 9

Hyponatremia results in

Answer 9

Less excitable, depolarization is delayed, decreased heart rate