诊断学课件器械检查部分房室大和心肌梗死

Part III Atrial Enlargement and Ventricular Hypertrophy 薛小临 (1) Left Atrial Enlargement Lead II nDuration of P wave 0.12 sec. ; nP wave become bifid (P “mitrale“); nThe distance of two peak 0.04sec. Lead V1 nP wave become biphasic; nPtfv1 - 0.04 mmsec Right Atrial Enlargement Lead II n P wave is peaked (P “pulmonale“); n Amplitude of P wave 0.25 mV in limb leads. Biatrial Enlargement Lead II n P wave duration and amplitude both increased. Left Ventricular Hypertrophy A. Increased voltage n SV1 + R V5 3.5mV (female), 4.0mV (male); n Rv5 or Rv6 2.5 mV; RI 1.5mV; RaVL 1.2mV; RaVF 2.0 mV; RI + SIII 2.5 mV; B. Left axis deviation C. ST depression and T inversion in V5-6. Right Ventricular Hypertrophy A. Increased voltage (adults over 30) n R/S ratio in V1 1.0; nR/S ratio in V5 or V6 1.0; nR/q or R/S ratio in aVR1; nR V1+ S V5 1.05mV (severe1.2mV); nRaVR0.5mV; B. Right axis deviation +900 (severe +1100). C. ST depression and T inversion V1-2. Biventricular Hypertrophy nA. Normal ECG. nB. One ventricular hypertrophy. nC. Biventricular Hypertrophy. Part VI Myocardial Ischemia and Myocardial infarction ECG of myocardial ischemia shows: nST segment depression; nST segment elevation( coronary spasm); nInverted, diphasic, low T wave. Myocardial infarction (1) Basic changes n“Hyperacute” T Waves. Tall peaked T waves, often appear as the earliest ECG sign of acute MI. n ST Elevations. The ST segment elevated in one or more leads and may be straightened and fuse with the T wave (mono-phasic curve) n Pathologic Q Waves. the sudden developed Q wave may indicate an acute MI. n T Wave Changes. The elevated ST segments return to the baseline, and deep symmetrical T waves appear in these leads. Tall, symmetrical, upright T waves will appear in reciprocal leads at the same time. (2) Progressive ECG changes (3) Localization of the ECG patterns Leads with Abnormal Q Waves in MI Leads with Abnormal Q Waves location of MI V1 V3 Anteroseptal V3 V5 Anterior I, aVL, V5 V6 Lateral V1 V6 Extensive Anterior II, III, aVF Inferior (4) Old myocardial