8/19- Sudden Cardiac Death Flashcards
(40 cards)
What are the biggest risk factors for atherosclerosis?
- High cholesterol
- HTN (> 140/90)
- Diabetes
- Smoking (current/recent!)
What are 2 broad diseases that can lead to heart failure?
- Coronary Artery Disease (from Atherosclerosis)
- Valvular Heart Disease
How can CAD (coronary artery disease) present?
- Arrhythmias -> Sudden Cardiac Death
- Angina (stable or unstable)
- Myocardial Infarction
What is included in “Acute Coronary Syndromes”?
- Unstable angina
- Myocardial infarction
T/F: > 1 million people suffer SCD/yr in the US
False
- 1300 cases/d (400,000/yr) in the US
T/F: The most common cause of SCD in adults is asystole
False
The most common cause of SCD in adults is ventricular fibrillation
- Primary VF is the most common cause of out-of-hospital SCD
- Asystole is usually the result of sustained myocardial anoxia during initial episode of VF rather than the primary cause of death
- Asystole is the MCC of SCD in infants
T/F: ASH/IHSS are the most common etiology of SCD in the US
False
- This is the most common etiology in 15-35 yo
- In general, most common cause is CAD
T/F: Most SCD are due to VF complicating AMI
False
T/F: VF without AMI rarely recurs unlike VF with AMI
False
Define: sudden cardiac death (SCD)
Sudden unexpected death due to cardiac causes occurring within one hour after the onset of cardiac symptoms
- NHLBI: death within 24 hrs of Sx
- WHO: un-witnessed death
- Uniformly fatal (unless successfully resuscitated; 1/3 survive)
Define: ventricular fibrillation (VF). What does the ECG look like?
Chaotic and asynchronous electrical ventricular activity arising from multiple foci and spreading erratically throughout the myocardium
Define: asystole (flat line “___”)
Asystole is usually the result of sustained myocardial anoxia during initial episode of VF rather than the primary cause of death
Define: primary vs. secondary VF
Primary VF: no associated MI
Secondary VF: associated MI (as proven by post-mortem changes on autopsy or cardiac enzymes)
What is the public health impact of SCD?
- 1300 cases/d (400,000/yr) in the US
- 50% of all CAD deaths
- 1/3 of all deaths age 20-64
- Gradual decline since 1971 (due to EMS, decreased coronary risk factors, and the coronary care unit)
Which has the higher recurrence: primary or secondary VF?
SCD recurrence is 5-10x higher in primary VF (that not associated with an MI)
- i.e. probably have some kind of factor/tissue very vulnerable to arrhythmias that hasn’t been fixed
Primary vs. Secondary VF:
- 55 yo man presents w/ crushing diffuse anterior chest pain 10/10 with diaphoresis and dyspnea
- No change in ECG or chest pain with SL NTG
What is the pt suffering from?
A. Acute massive viral pericarditis
B. Unstable angina with a “platelet plug”
C. LAD Vasospasm refractory to SL NTG
D. Acute ST elevation MI due to fibrin/RBC “red” clot completely occluding the LAD
E. Intense coronary constriction due to anxiety
ECG: acute anterolateral MI
- Local ST elevation (leads I, aVL, and V2-V5)
- Acute MI likely due to occlusion in the pulmonary artery (?)
What is the pt suffering from?
A. Acute massive viral pericarditis
B. Unstable angina with a “platelet plug”
C. LAD Vasospasm refractory to SL NTG
D. Acute ST elevation MI due to fibrin/RBC “red” clot completely occluding the LAD
E. Intense coronary constriction due to anxiety
Primary vs. Secondary VF (pt 2):
- 55 yo man who presented with chest pain sustains a sudden unexpected cardiac arrest 3-4 hrs later
- How would you manage him after initial resuscitation?
- How likely is recurrent SCD after hospital discharge?
- This was a secondary cardiac arrest (or secondary VF); SCD associated with MI
- Chance of recurrence is low; no need for ICD after discharge
Which of the following best applies to this 55 yo man (with chest pain and unexpected cardiac arrest 3-4 hrs later)?
A. Primary VF
B. Secondary VF
C. Massive anterolateral MI complicated by VF
D. Low risk of recurrent SCD
E. B, C, and D
Which of the following best applies to this 55 yo man (with chest pain and unexpected cardiac arrest 3-4 hrs later)?
A. Primary VF
B. Secondary VF
C. Massive anterolateral MI complicated by VF
D. Low risk of recurrent SCD
E. B, C, and D
What is an AICD? For who is it routinely recommended?
Automatic Implantable Cardioverter Defibrillator (or just ICD)
- Routinely recommended for primary VF (high chance of recurrence); NOT recommended for secondary
What can an AICD do? (Don’t need to memorize)
- Provide shock in cases of ventricular fibrillation (VF)
- ATP- anti-tachycardiac pacing- try to recognize VT before above shock is required (will pace ventricle faster for just a few s in “overdrive pacing”)
What is this?
Ventricular fibrillation
What is the most common cause of SCD?
Tachy-arrhythmias
- Ventricular fibrillation**
- Ventricular tachycardia
- Ventricular flutter
Brady-arrhythmias
- Asystole
- Bradycardia
What is this?
Ventricular Tachycardia (3+ consecutive beats)
What is VT and AIVR? Features?
VT- ventricular tachycardia
AIVR - accelerated idioventricular rhythm
- Both are wide QRS regular tachycardia with no P (but AIVR does not -> SCD)
- VT has a rate >110/min while AIVR is under 110/min; this is the only difference!
