The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study util...The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study utilizing free-breathing and static DIBH scans from eleven patients treated with radiotherapy for breast cancer. The anterior-posterior displacement along the length of the LAD was measured in each respiratory phase. Standard treatment plans targeting the whole breast without treatment of the internal mammary lymph nodes were generated and dose to the LAD and LV calculated. Non-uniform movement of the LAD during respiratory maneuvers with the proximal third exhibiting the greatest displacement was observed. In DIBH compared to end-expiration (EP), the mean posterior displacement of the proximal 1/3 of the LAD was 8.99 mm, the middle 1/3 of the artery was 6.37 mm, and the distal 1/3 was 3.27 mm. In end-inspiration (IP) compared to end-expiration the mean posterior displacements of the proximal 1/3 of the LAD was 2.08 mm, the middle 1/3 of the artery was 0.91 mm, and the distal 1/3 was 0.97 mm. Mean doses to the LAD using tangential treatment fields and a prescribed dose of 50.4 Gy were 11.32 Gy in EP, 8.98 Gy in IP, and 3.50 Gy in DIBH. Mean doses to the LV were 2.38 Gy in EP, 2.31 Gy in IP, and 1.24 Gy in DIBH. In conclusion, inspiration and especially DIBH, cause a displacement of the origin and proximal 2/3 of the LAD away from the chest wall, resulting in sparing of the most critical segment of the artery during tangential radiotherapy.展开更多
Introduction: To present a rare occurrence of “Swiss-cheese” defects of left ventricle in acute myocardial infarction. Case Report: A 64-year-old male with persistent ST segment elevation in anterior and inferior le...Introduction: To present a rare occurrence of “Swiss-cheese” defects of left ventricle in acute myocardial infarction. Case Report: A 64-year-old male with persistent ST segment elevation in anterior and inferior leads developed sudden deterioration within 2 days after thrombolysis. Echocardiography revealed ventricular septal and LV (left ventricular) free wall ruptures at multiple sites with contractile dysfunction and the patient died suddenly, followed by an episode of ventricular tachycardia. Discussion: Myocardial rupture may complicate in 10% of acute myocardial infarctions and it is the second most common cause of in-hospital mortality next to pump failure. It is responsible for 15% of in-hospital deaths and 50% died within 5 days and 82% died within two weeks of index infarction. Conclusion: Aggressive early diagnosis and surgery may confer a survival rate as high as 75%. The prognosis is grave in patients presented with cardiogenic shock and multiorgan dysfunction;surgery is best avoided and supportive medical therapy may be adequate in such cases.展开更多
文摘The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study utilizing free-breathing and static DIBH scans from eleven patients treated with radiotherapy for breast cancer. The anterior-posterior displacement along the length of the LAD was measured in each respiratory phase. Standard treatment plans targeting the whole breast without treatment of the internal mammary lymph nodes were generated and dose to the LAD and LV calculated. Non-uniform movement of the LAD during respiratory maneuvers with the proximal third exhibiting the greatest displacement was observed. In DIBH compared to end-expiration (EP), the mean posterior displacement of the proximal 1/3 of the LAD was 8.99 mm, the middle 1/3 of the artery was 6.37 mm, and the distal 1/3 was 3.27 mm. In end-inspiration (IP) compared to end-expiration the mean posterior displacements of the proximal 1/3 of the LAD was 2.08 mm, the middle 1/3 of the artery was 0.91 mm, and the distal 1/3 was 0.97 mm. Mean doses to the LAD using tangential treatment fields and a prescribed dose of 50.4 Gy were 11.32 Gy in EP, 8.98 Gy in IP, and 3.50 Gy in DIBH. Mean doses to the LV were 2.38 Gy in EP, 2.31 Gy in IP, and 1.24 Gy in DIBH. In conclusion, inspiration and especially DIBH, cause a displacement of the origin and proximal 2/3 of the LAD away from the chest wall, resulting in sparing of the most critical segment of the artery during tangential radiotherapy.
文摘Introduction: To present a rare occurrence of “Swiss-cheese” defects of left ventricle in acute myocardial infarction. Case Report: A 64-year-old male with persistent ST segment elevation in anterior and inferior leads developed sudden deterioration within 2 days after thrombolysis. Echocardiography revealed ventricular septal and LV (left ventricular) free wall ruptures at multiple sites with contractile dysfunction and the patient died suddenly, followed by an episode of ventricular tachycardia. Discussion: Myocardial rupture may complicate in 10% of acute myocardial infarctions and it is the second most common cause of in-hospital mortality next to pump failure. It is responsible for 15% of in-hospital deaths and 50% died within 5 days and 82% died within two weeks of index infarction. Conclusion: Aggressive early diagnosis and surgery may confer a survival rate as high as 75%. The prognosis is grave in patients presented with cardiogenic shock and multiorgan dysfunction;surgery is best avoided and supportive medical therapy may be adequate in such cases.
