Origin of the giant R wave in acute transmural myocardial infarction in the pig.

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概要

• 論文の詳細を見る

• An increase in R wave amplitude and a diminution of S wave amplitude, together with ST segment elevation, have been described as very early electrocardiographic changes during clinical and experimental acute myocardial infarction. The genesis of these QRS changes remains unclear. We assessed the quantitative relationship between the local conduction delay and the formation of the giant R wave, using multiple epicardial, intramural unipolar, and bipolar electrodes in 30 open-chest pigs with acute transmural myocardial ischemia. Blood pressure, heart rate, serum electrolytes, hematocrit, and left ventricular size remained constant, or varied insignificantly throughout the experiments. In nonischemic pigs, transmural left ventricular activation occurred nearly simultaneously, and the activation time was not correlated with the net QRS potential. During acute ischemia, a giant R wave developed at all of the electrodes located within the ischemia region; R wave amplitude began to increase 1min after coronary artery ligation (p<0.05), compared to control amplitude and peaked at 8min (p<0.0001). The degree of conduction delay at a given site was correlated linearly with the local R wave amplitude (average of correlation coefficients±SEM at 1min, r=0.64±0.08, and at 8min, r=0.81±0.06). The magnitude of the R wave potential and the conduction delay were greater in regions deep inside the ischemic zone than in the border and normal areas (p<0.0001), and were greater in subepicardial than in subendocardial areas (p<0.05). In summary, during transmural ischemia, conduction is markedly slowed, and an orderly and discrete wavefront advances toward the center of the ischemic zone from lateral and subendocardial areas. When depolarization is complete in the rest of the heart, this slow activation front becomes temporally isolated and its progression gives rise to a giant R wave, which appears in recordings from overlying electrodes.

• International Heart Journal刊行会の論文

著者

• Akiyama Toshio

  Cardiology Unit University Of Rochester Medical Center

• AKIYAMA Toshio

  Cardiology Unit, Department of Medicine, University of Rochester Medical Center

• CHANG Winshih

  Cardiology Unit, Department of Medicine, University of Rochester Medical Center

• RICHESON J.

  Cardiology Unit, Department of Medicine, University of Rochester Medical Center

• FAILLACE Robert

  Cardiology Unit, Department of Medicine, University of Rochester Medical Center

• SERRINO Peter

  Cardiology Unit, Department of Medicine, University of Rochester Medical Center

関連論文

• 5 Medical Residency Programs of the U.S. and Japan(Current Issues in New Residency System in Japan, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• Sudden Cardiac Death : Results of Multicenter Randomized Clinical Trials
• Origin of the giant R wave in acute transmural myocardial infarction in the pig.
• The giant R wave of acute myocardial infarction.

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