心律失常总论(英文版)完整版.pptVIP

ELECTROCARDIOGRAM “5” steps approach to arrhythmias Step1: Is there a “QRS” Step2: Is there a “P” Wave Step3: What is the relationship between the P waves and the QRS complexes? Step4: Calculate rate Step5: Miscellaneous Step 1: Is there a “QRS” (No pulse) YES NO CHAOTIC FLAT LINE WIDE NARROW PEA VF Asystole VT Step 2: Is there a “P” Wave YES NO VARY CONSTANT MORPHOLOGY RATE 220 to 350 AF JUNCTIONAL Inverted RR Interval JUNCTIONAL Atrial Flutter Step 3: What is the relationship between the P waves and the QRS complexes? 0.2 Normal 0.2 Io AVB Constant ? Yes IIo AVB type 2 No RR interval Yes IIIoAVB No Type1 IIo PR interval PR interval HEART BLOCK n“P” = n“QRS” ? No Yes Constant? 1st Degree block(AV Nodal Delay) Event Monitors Holter monitoring: Document symptomatic and asymptomatic arrhythmias over 24-48 hours. Can also evaluate treatment effectiveness in a-fib, pacemaker effectiveness and identify silent MIs. Trans-telephonic event recording: patient either wears monitor for several days or attaches it during symptomatic events and an ECG is recorded and transmitted for evaluation via telephone. Only 20% are positive, but still helpful. Exercise testing Symptoms only appear or worsen with exercise. Also used to evaluate medication effectiveness (esp. flecanide propafenone) ?You can assess SA node function with exercise testing. ?Mobitz 1 (Wenkebach) is blockage at the AV node, so catecholamines from exercise actually help! ?Mobitz 2 is blockage at bundle of His, so it worsens as catecholamines from exercise increase AV node conduction, thus prognosis is worse. *PVCs occur in 10% without and 60% of patients with CAD. *PVCs DO NOT predict severity of CAD (neither for nor against)! Signal Averaged ECG Used only in people post MI to evaluate risk for v-fib or v-tach. Damage around the infarct is variable, so this measures late potentials (low-signal, delayed action potentials) as they pass through damaged areas. Posit