Cardiology Flashcards
Which main coronary supplies the following:
1) SA node
2) AV node
1) Proximal RCA (65%) or LCx (25%), both (10%)
2) RCA (80%), LCX (10%), both (10%)
Average HR drop during sleep in [1] young healthy adults and [2] elderly?
24 bpm
14 bpm
Symptoms of Bradycardia?
Asymptomatic
Fatigue
Weakness
Light-headedness
Syncope
Physical findings of bradycardia?
Slow pulse rate
Hypotension
Cool extremities
Cannon A waves (in setting of AV dissociation)
What is a junctional escape rhythm?
- Rhythm 40-60bpm
- No visible P waves before QRS
- QRS typically <120ms
Causes of sinus bradycardia? (intrinsic vs extrinsic to SA node)
1) Intrinsic to SA node
- idiopathic degeneration (aging)
- ischemia (esp. inferior)
- infiltrative (e.g., amyloidosis)
- collagen vascular disease (e.g., SLE)
- infectious (e.g., Chagas, myocarditis, Lyme)
- myotonic dystrophy
- surgical trauma (e.g., valve replacement)
2) Extrinsic to SA node
- meds (e.g., bb, ccb, digoxin, clonidine, amio, opioids)
- lytes (e.g., low/high K+)
- neurally-mediated reflexes (e.g., carotid sinus hypersensitivity)
- hypothyroidism
- hypothermia
- brainstem herniation
Common meds associated with sinus bradycardia?
- bb
- ccb
- digoxin
- clonidine
- antiarrhythmic agents (e.g., amiodarone, lidocaine)
Typically, infections leads to increase in temperature with corresponding increase in heart rate. Which infections are associated with relative bradycardia?
- Legionella
- Pscittacosis
- Q fever
- Typhoid fever
- Typhus
- Babesiosis
- Malaria
- Leptosporiasis
- Yellow fever
- Dengue fever
- Viral hemorrhagic fevers
- Rock Mountain spotted fever
How often is Mobitz II AV block associated with a wide QRS?
Wide: 80%
Narrow: 20%
ECG diagnosis of STEMI?
- > 0.1 STE in 2 contiguous leads
- EXCEPT in V2-3 - must be >0.2 (men) and >0.25 (women)
What is the typical evolution of ECG changes associated with ischemia?
- Hyperacute: tall T waves
- Acute: STE
- Hours: STE + reduced R wave + Q wave
- Day 1-2: TWI, Q-wave deeper
- Days: ST normalizes, TWI
- Weeks: ST/TW normal, Q wave persists
Which conditions make ECG interpretation of ischemia unreliable?
- early repolarization
- LVH
- LBBB
- ventricular paced rhythm
- preexcitation
- J-point elevation syndromes (e.g., Brugada)
- pericarditis/myocarditis
- SAH
- hyperK+
- stress CM
- cholecystitis
Risks associated with acute aortic dissection?
- male
- age: >60
- HTN
- prior cardiac sx (esp AV repair)
- bicuspid AV
- connective tissue (eg., marfan)
- aortitis (eg., GCA, syphilis)
Why do MVP patients who undergo repair can oftenhave persistent episodes of chest pain + palpitations after repair?
Autonomic dysfunction that persists after repair
Definitive diagnostic study for pulmonary hypertension?
- Gold: right heart cath
- Other: TTE, ECG, PFT
S3 vs S4?
1) S3
- early diastolic
- r/t rapid ventricualr filling
- DDx: ADHF, DCM, thyrotoxicosis, AR
2) S4
- late diastolic
- r/t late atrial kick against stiff ventricle
- DDx: HTN, AS, cor pulm, ischemic CM, acute MI