HEART RHYTHMS * 0.4 sec is the PR wave (it is actually the P-Q wave but called the PR wave) and it should be ≤ 0.20 sec. If it’s ≥ than that it indicates 1° heart block. * NSR: normal sinus rhythm, contraction originates from SA node and beats at 60-100 bpm * Sinus (atrial) Bradycardia: SA node discharges at < 60 bpm. TREATMENT is atropine and pacemaker if they become symptomatic. Usually the contractions are irregular but the same distance apart so they are irregular-regular * Sinus Tachycardia (atrial dysrhythmias): SA node discharges at > 100 bpm. Regular but fast; they won’t have heart block because the SA node is firing too rapidly. TREATMENT is BB or CCB to ↓ HR and BP * PAC (Premature Atrial Contraction): impulse travels across atria via abnormal pathway, creating a disturbed P wave. Contraction originates from ectopic focus in atrium other than the SA node. Caffeine and diet pills predispose people to these but they don’t adversely affect health. TREATMENT is none. * Atrial Flutter: atrial tachycardia resulting in recurring, regular sawtooth flutter waves. The ratio of atrial to ventricle contractions is 3:1. TREATMENT is synchronized cardioversion (like defibrillation but the less Joules, 150-200 vs 300, and you must push the “sync” button to synchronize the energy so as to not direct it onto the T wave and send the patient in V-fib) and ablations. * Valve Replacement: patient must be put on blood thinner afterwards and must be anticoagulated more than normal. 3-4x INR vs 1.5-2x INR * Atrial Fibrillation: total disorganization of atrial activity and ineffective atrial contractions. TREATMENT is Coumadin (to prevent DVTs) or Xarelto. You want a skinny QRS wave which is about 0.12 seconds; a wide one is bad. Elevated T wave indicates ischemia. * 1° Heart Block: each impulse is directed to the ventricles but the