Mod10 Sudden Cardiac Death Flashcards
Sudden Cardiac Death (SCD)
unexpected natural death resulting from cardiovasc abnormality occuring shortly after the onset symptoms in individuals that appear otherwise healthy; usually caused by sustained VT
Most common substrate for SCD
ischemic heart disease
Influences of SCD
AGE (increase risk with age; responsible for 20% of deaths of pp under 20), RACE (african american have highest incidence followed by white, then asian). GENDER (rates are higher in men)
RF’s of SCD (similar to those of atherosclerotic CAD)
Underlying CAD (80%) (or history of); Smoking, Hypertension, Cholestrol, Alcohol, Diabetes
Abnormalities that are predictive of SCD
arrhythmia, premature ventricular contractions (PVCs), left ventricular hypertrophy, cardiomegaly
Triggers of Tachyarrhymias
ischemia and electrolyte imbalance; know these triggers in order to eliminate these factors
Mechanisms of SCD
Structure and function, Tachyarrythmias, Ischemia, mechanoelectrical feedback
Structure and function
1/4 mechanisms of SCD; cardiac structural abnormalities are common in SCD; these provide substrate for ventricular tachyarrythmias
Tachyarrhythmias
1/4 mechanisms of SCD; VF is first recorded rhythm in 75% of patients that have cardiac arrest; VT generally degenerates into VF; asysole is a later manifestation of cardiac arrest (CA)
Ischemia
1/4 mechanisms of SCD; Acute MI causes Acidosis affecting membrane integrity; this causes electrical abnormalities causing conduction delays, unidirectional blocks and reentrant arrhythmias
Mechanoelectrical Feedback
1/4 mechanisms of SCD; altered contractility and preload have electrophysiologic effects that may ppt arrhythmias
Management of SCD requires immediate:
early assessment, early CPR, early defibrillation and early cardiac life support
Defibrillation
essential for management of acute cardiac arrest
AED
portable electronic device that helps the heart return to normal rhythm
Steps of CPR
if not AED start CPR immediately; start with COMPRESSIONS (push down atleast 2inches at 100/min; push on chest 30times, AIRWAYS: open airway by tilting head backward and lift chin; BREATHING give two mouth to mouth breaths with 2 sec btw. REPEAT
Management of Cardiac Arrest Survivors
prompt stabilization of patient’s cardiopulmonary status; detect and treat any potential triggers; take patients history, give thorough exam, lab test, ECG and catheterization; IF AT HIGH RISK= treat underlying associated heart condition
Treatment options of SCD
DRUGS (b-blockers, ace inhibitors, hydroxymethylglutaryl-coenzyme A reductase inhibitor, sotalol, amiodarone), IMPLANTED CARDIOVERTER DEFIB (ICD)
B-blockers
treatment option for SCD; stabilizes autonomic balance; improves contractility and reduces ischemia
ACE inhibitors
treatment option for SCD; reduction in pump failure (similar to B-blockers)
Hydroxymethylglutaryl-Coenzyme A Reductase Inhibitors
reduces incidence of coronary plaque rupture and/or platelet aggregation/thrombosis
Amiodarone
treatment option for SCD; most effective antiarrythmic agent for therapy of tachyarrhythmias
Implanted cardioverter defibrillator (ICD)
used as an intervention/prevention measure; they recognize and internally cardiovert VT or defibrillate VF soon after its initiation