Cardiac Flashcards
Atrial Fibrillation IV Rate control
- Diltiazem 0.25 mg/kg IV
- follow with drip (start at 5-10 mg/h)
- Metoprolol 2.5-5 mg IV q 5-10 min
- Phenylephrine may be good adjunct
Rx for unstable patients with suspicion of atrial fibrillation as the etiology of instability
synchronized cardioversion, 200 J biphasic shock
Conversion of patients who have permanent AF may be futile, as most will not convert.
Acute Coronary Syndromes Rx
- ASA 162-325 mg PO
- Unfractionated heparin: 5,000 units (≥50 kg)
- Consider a P2Y12 inhibitor:
- — Clopidogrel 600 mg or ticagrelor 180 mg PO
What is a normal QRS duration?
Less than 100
What is the effect of placing a magnet over a pacemaker?
It converts it to fixed-rate pacing mode.
What is the dose of intravenous magnesium sulfate for torsade de pointes?
1-2 g IV
What agents should be avoided in patients with atrial fibrillation and Wolf-Parkinson-White (WPW) syndrome?
AV-nodal blocking agents such as adenosine, calcium channel blockers, beta-adrenergic blockers, and digoxin. This can lead to cardiovascular collapse due to preferential accessory pathway conduction.
Aortic Dissection
Treatment
2-drug strategy
Treatment is reduce BP/HR
2-drug strategy:
1st: β-blockade- Esmolol IV is preferred
2nd: antihypertensive- Nicardipine IV
Aortic Dissection
Treatment
1-drug strategy
Labetalol IV 10-20 mg bolus over 2 min –> drip
Labetalol IV has 7 times more beta blocker activity than alpha blocker activity; therefore, often inadequate for blood pressure control.
Aortic Dissection
Hemodynamic goals
HR <60 beats/min.
Systolic blood pressure <120 mm Hg
In the event of blood pressure discrepancy among extremities, dose the antihypertensive medication based on the extremity with the higher SBP.
Ventricular Tachycardia
Unstable: rx
Patients with unstable tachydysrhythmias should receive immediate synchronized cardioversion (150−200 J biphasic)
If unsure, manage all wide complex tachycardias as ventricular tachycardia
