8/20- Sudden Cardiac Death- CASES

Question 1

What is sudden cardiac death?

Answer 1

Sudden, unexpected death occurring within 1 hr of the presence of symptoms (here, actually “instantaneous cardiac death”

Question 2

What is the commonest etiologic cause of SCD in the US?

A. Valvular heart disease

B. Cardiomyopathy

C. Coronary artery disease

D. Pericardial disease

Answer 2

What is the commonest etiologic cause of SCD in the US?

A. Valvular heart disease

B. Cardiomyopathy

C. Coronary artery disease

D. Pericardial disease

Question 3

Is patient’s age useful in predicting the underlying cause of SCD?

Answer 3

Yes

Most common etiology of SCD:

• MIddle aged and older adults: CAD
• 15-35 yo: IHSS (also ARVD)

Overall, CAD is the most common cause

Question 4

What does “biphasic” mean in regards to ECGs?

Answer 4

Having 2 phases- one positive and one negative

Question 5

What does a biphasic P wave in lead I mean?

Answer 5

Sensitive but nonspecific finding of left atrial enlargement

Question 6

Which of the following is an ECG voltage criterion for LVH?

A. Tall R wave in V5/6 and Deep S wave in V1/V2 adding up (R+S) to at least 35 mm

B. Tall R wave in V1 or V2 and Deep S wave in V5/V6…

C. R in any lead > 35 mm…

D….

Answer 6

Which of the following is an ECG voltage criterion for LVH?

A. Tall R wave in V5/6 and Deep S wave in V1/V2 adding up (R+S) to at least 35 mm

B. Tall R wave in V1 or V2 and Deep S wave in V5/V6…

C. R in any lead > 35 mm…

D….

Question 7

What does it mean if patient has:

• Bifid P wave
• Tall R wave in V5/6 and Deep S wave in V1/V2 adding up (R+S) to at least 35 mm

Answer 7

Left ventricular hypertrophy (voltage) and Left atrial enlargement (bifid P wave)

Question 8

With a positive family Hx at young age, how do you explain exertional chest pains and dizziness in this pt (LVH and LAE)?

A. Dilated cardiomyopathy

B. Restrictive cardiomyopathy

C. Aortic stenosis due to bicupsid aortic valve

D. Hypertrophic cardiomyopathy

Answer 8

With a positive family Hx at young age, how do you explain exertional chest pains and dizziness in this pt (LVH and LAE)?

A. Dilated cardiomyopathy

B. Restrictive cardiomyopathy

C. Aortic stenosis due to bicupsid aortic valve

D. Hypertrophic cardiomyopathy

Question 9

What is the mechanism of the systolic murmur in this pt (LVH, LAE with HCM)?

A. Narrowing of the aortic valve

B. Septal hypertrophy

C. Obstruction in the LVOT due to septal hypertrophy

D. Dilated ventricle

E. Mitral regurgitation

Answer 9

What is the mechanism of the systolic murmur in this pt (LVH, LAE with HCM)?

A. Narrowing of the aortic valve

B. Septal hypertrophy

C. Obstruction in the LVOT due to septal hypertrophy

D. Dilated ventricle

E. Mitral regurgitation

Question 10

How do you explain the louder and longer systolic murmur with standing (LVH/LAE due to HCM)?

A. Greater venous return

B. Small venous return

C. Smaller LV size

D. Greater contractility

E. B and C

Answer 10

How do you explain the louder and longer systolic murmur with standing (LVH/LAE due to HCM)?

A. Greater venous return

B. Small venous return

C. Smaller LV size

D. Greater contractility

E. B and C

Question 11

You noticed a weaker pulse following a pause (in this pt with LVH/LAE due to HCM). Is this normal and why?

A. Yes, due to reduced preload

B. Yes, due to reduced contractility

C. No, it is due to higher contractility worsening the LVOT obstruction

Answer 11

You noticed a weaker pulse following a pause (in this pt with LVH/LAE due to HCM). Is this normal and why?

A. Yes, due to reduced preload

B. Yes, due to reduced contractility

C. No, it is due to higher contractility worsening the LVOT obstruction

Question 12

What is post-extrasystolic potentiation?

Answer 12

Beat after pause (from early beat) normally results in stronger subsequent beat.

Due to:

• Increased preload
• Increased contractility

Question 13

What happens to cardiac output in IHSS if you increase contractility? Preload?

Answer 13

• Greater contractility decreases CO in IHSS
• Greater preload increases CO in IHSS

(In BWB phenomenon, contractility outweighs preload and beat following pause will be weaker; decreased CO)

Question 14

Why is this pt (LVH/LAE with HCM) dizzy after exertion?

A. Venous pooling sharply REDUCES preload thus wrosening the LVOT obstruction

B. Venous pooling sharply INCREASES contractility thus worsening the LVOT obstruction

C. I am not really sure

Answer 14

Why is this pt (LVH/LAE with HCM) dizzy after exertion?

A. Venous pooling sharply REDUCES preload thus wrosening the LVOT obstruction

B. Venous pooling sharply INCREASES contractility thus worsening the LVOT obstruction

C. I am not really sure

Question 15

What is the most likely cause of SCD in this pt (LVH/LAE with HCM)?

A. Exercise induced VT/VFIB

B. AFIB due to WPW

C. Severe heart failure

D. Heart just gave up

Answer 15

What is the most likely cause of SCD in this pt (LVH/LAE with HCM)?

A. Exercise induced VT/VFIB

B. AFIB due to WPW

C. Severe heart failure

D. Heart just gave up

• Exercise increases oxygen demands
• Oxygen demand outstrips supply of blood to myocardium, causing ischemia
• Myocardium is pro-arrhythmic substrate

Question 16

Does hypertrophy itself interfere with conduction in the heart (itself)?

Answer 16

No

Question 17

Possibilities for early diastolic extra sound

Answer 17

• A2/P2 fixed ?
• Atrial myxoma
• Mitral stenosis (opening snap)
• Aortic regurgitation

Question 18

What is the most likely cardiac disease predisposing this episode of SCD (pt 2: HTN, smoking, past hx of MIs)?

A. Atherosclerosis

B. Valvular heart disease

C. Idiopathic DCM

D. HCM

Answer 18

What is the most likely cardiac disease predisposing this episode of SCD (pt 2: HTN, smoking, past hx of MIs)?

A. Atherosclerosis

B. Valvular heart disease

C. Idiopathic DCM

D. HCM

Question 19

What clinical syndrome explains his cardiomegaly, hypokinetic LV, and low EF of 28% (pt has atherosclerosis)?

A. CHF due to ischemic CM

B. CHF due to HCM

C. CHF due to idiopathic DCM

D. CHF due to alcohol-related DCM

Answer 19

What clinical syndrome explains his cardiomegaly, hypokinetic LV, and low EF of 28% (pt has atherosclerosis)?

A. CHF due to ischemic CM

B. CHF due to HCM

C. CHF due to idiopathic DCM

D. CHF due to alcohol-related DCM

Question 20

Could prolonged QT predispose to SCD in this pt?

A. Yes, since it may cause VT or VFIB

B. Yes, since it may cause AV block

C. No, because only short QT causes SCD D. No, because only short QT causes VT or VFIB

Answer 20

Could prolonged QT predispose to SCD in this pt?

A. Yes, since it may cause VT or VFIB

B. Yes, since it may cause AV block

C. No, because only short QT causes SCD D. No, because only short QT causes VT or VFIB

Question 21

If this pt had ST elevation relieved with SL NTG and had NO elevation of cardiac enzymes, what is the most likely cause of SCD?

A. Primary SCD due to V Fib

B. Secondary SCD due to VT

C. Secondary SCD associated with CHF

Answer 21

If this pt had ST elevation relieved with SL NTG and had NO elevation of cardiac enzymes, what is the most likely cause of SCD?

A. Primary SCD due to V Fib

B. Secondary SCD due to VT

C. Secondary SCD associated with CHF

• Recall, primary SCD is NOT accompanied by heart attack (concomitant myocardial infarction)

Question 22

T/F: the likelihood of recurrent SCD is greater if he had suffered an cute MI?

Answer 22

False?

• Greater chance of recurrence with primary SCD (no MI)