Paradoxic Decrease in Ischemic Mitral Regurgitation With Papillary Muscle Dysfunction

• Emmanuel Messas

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• J. Luis Guerrero

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• Mark D. Handschumacher

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• Chi-Ming Chow

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• Suzanne Sullivan

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• Ehud Schwammenthal

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

• Robert A. Levine

  From the Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Dr Messas is presently affiliated with Faculte de Medicine Necker-Enfants Malades, Service de Cardiologie 1, HEGP Hopital, Paris, France. Dr Schwammentnal is presently at the Heart Institute, Chaim Sheba Medical Center, Tel HaShomer, Israel.

書誌事項

タイトル別名

• Insights From Three-Dimensional and Contrast Echocardiography With Strain Rate Measurement

抄録

Background Ischemic mitral regurgitation (MR) was first ascribed to papillary muscle (PM) contractile dysfunction. Current theories include apical leaflet tethering caused by left ventricular (LV) distortion, but PM dysfunction is still postulated and commonly diagnosed. PM contraction, however, parallels apical tethering, suggesting the hypothesis that PM contractile dysfunction can actually diminish MR due to ischemic distortion of the inferior base alone. Methods and Results We therefore occluded the proximal circumflex circulation in 7 sheep while maintaining PM perfusion, confirmed by contrast echocardiography. By 3D echocardiography, we measured the tethering distance between the ischemic medial PM tip and anterior annulus and LV ejection volume to give MR (by subtracting flowmeter LV outflow). In 6 sheep without initial MR, inferior ischemia alone produced PM tip retraction with restricted leaflet closure and mild-to-moderate MR (regurgitant fraction, 25.2±2.8%). Adding PM ischemia consistently decreased MR and tethering distance (5.2±0.3 to 1.4±0.3 mL; +3.8±0.5 mm to −2.2±0.7 mm axially relative to baseline; P <0.001) as PM strain rate decreased from +0.78±0.07 per second (contraction) to −0.42±0.06 per second (elongation, P <0.001) and leaflet tenting decreased. In one sheep, prolapse and MR resolved with inferior ischemia and recurred with PM ischemia. Conclusions PM contractile dysfunction can paradoxically decrease MR from inferobasal ischemia by reducing leaflet tethering to improve coaptation. This emphasizes the role of geometric factors in ischemic MR mechanism and potential therapy.

収録刊行物

• Circulation

  Circulation 104 (16), 1952-1957, 2001-10-16

  Ovid Technologies (Wolters Kluwer Health)

キーワード

• Physiology (medical)
• Cardiology and Cardiovascular Medicine

詳細情報

• CRID: 1363388844418582400
• NII論文ID: 30029738301
• DOI: 10.1161/hc4101.097112
• ISSN: 15244539
• ISSN: 00097322
• ISSN: http://id.crossref.org/issn/00097322
• Web Site: https://www.ahajournals.org/doi/full/10.1161/hc4101.097112
• データソース種別:
  • Crossref
  • CiNii Articles