Cardiovascular

▪ACLS 2005 AHA Guidelines

VF and Pulseless VT: CPR; manual biphasic 200 J, or monophasic 360 J; intubate; epinephrine 1 mg IV/IO q 3-5 min ◊ 1 (no max) or vasopressin 40 u IVP; shock after every med with manual biphasic at 200 J, or monophasic at 360 J; amiodarone 300 mg IVP (D5W only), then consider additional 150 mg IV/IO once, or lidocaine 1-1.5 mg/kg q 3-5 min (max 3 mg/kg); magnesium 1-2 g IV/IO.

PEA/Asystole: CPR; check underlying cause*; epinephrine 1 mg IVP/IO q 3-5 min (no max), or vasopressin 40 u IV/IO to replace first or second dose of epi; consider atropine 1.0 mg IV q 3-5 min (max 0.04 mg/kg); draw ABGs & electrolytes. Do NOT defibrillate.

Narrow Sinus Tachy:

Stable Narrow Tachy: Vagal maneuvers**; adenosine 6 mg rapid IVP; adenosine 12 mg rapid IVP (may repeat 12 mg dose once); amiodarone 150 mg IV over 10 min, repeat as necessary to maximum dose of 2.2 grams/24 hrs; verapamil 2.5 mg IV, may repeat with 5-10mg IV; beta blockers, digitalis.

Unstable Narrow Tachy: Sedate; synchronized cardioversion 100, 20, 300, 360 J.

Wide Tachy:

Cardiovert 200, 300, 360 J or amiodarone 150 mg IV over 10 min, repeat as necessary to maximum dose of 2.2 grams/24 hrs.

VT with Pulse:

Stable EF: Amiodarone 150 mg IV over 10 min, repeat as necessary to ◊ 150 mg IV over 10 min, repeat as necessary to maximum dose of 2.2 grams/24 hrs (D5W only); prepare for elective synchronized cardioversion.

Poor EF: Amiodarone 1/2 dose; lidocaine 1/2 dose; synchronized cardioversion.

Differential Diagnosis

* Underlying causes per ACLS guidelines: Hypo/hyperkalemia, hypoxia, hypothermia, hypovolemia, hypoglycemia, acidosis, drug OD (Tricyclics, beta blockers, calcium channel blockers, digitalis), cardiac tamponade, tension pneumothorax, coronary thrombosis, PE, trauma (increased ICP).

**Vagal maneuvers: Hard cough, facial immersion in cold water, gag reflex stimulation, squatting, and carotid sinus massage.

Treatment of atrial fibrillation/flutter.

▪EKG

Normal 12-lead EKG. Volatile agents prolong AV conduction (H > E > I); atropine reverses these effects.

12-Lead EKG Abnormalities

Left axis deviation (LAD): Common; L1 pos QRS, AVF neg QRS.
Right axis deviation (RAD): Less common; L1 neg QRS, AVF pos QRS.
Indeterminate deviation; L1 neg QRS, AVF neg QRS.
Q wave normal only in AVR; if > 0.04 sec or > 1 mm deep, then damage indicated.
RBBB common, not dg of CV disease; RSR prime V₁-V₂ with QRS > 0.12 sec.
LBBB = CAD, HTN, LVH; RSR prime in V₅-V₆ with QRS > 0.12 sec.
Left anterior hemiblock (LAH) longer, thinner fascicle, single blood supply, associated with LAD; common. Negative QRS in 2, 3, AVF:

Small Q—I, AVL

Small R—2, 3, AVF

OR RBBB with LAD
Left posterior hemiblock (LPH) short, thick fascicle, dual (RCA, circumflex) blood supply, assoc with RAD;

Positive QRS in 2, 3, AVF:

Small R—I, AVL

Small Q—2, 3, AVF
Bifasicular: RBBB and one of left branches; RBBB with LAH common.