Assessment of transient ischemic dilation (TID) ratio in gated SPECT myocardial perfusion imaging (MPI) using regadenoson, a new agent for pharmacologic stress testing.

BACKGROUND: Abnormal values of the transient ischemic dilation (TID) ratio are associated with severe and extensive coronary artery disease (CAD). The objective of this study was to determine the relationship between TID, determined from stress and rest ventricular volumes during regadenoson gated single-photon emission computed tomography myocardial perfusion imaging (MPI) dual isotope studies, and the extent of CAD found during coronary angiography. METHODS: 195 patients who underwent dual isotope MPI with regadenoson and cardiac angiography between March 2009 and February 2010 were analyzed. TID was calculated using commercially available software, Emory Cardiac Toolbox. Mean TID values were compared across disease types. A threshold for abnormal TID was determined by adding two standard deviations (SDs) to the mean TID of the "non-obstructive CAD" subgroup. RESULTS: In the 195-patient group analyzed, the mean TID ratio for non-obstructive CAD (n = 104) was found to be 1.09 with a SD of 0.15. In a subgroup of patients whose angiogram was within 3 months of MPI (n = 155), the mean TIDs for non-obstructive disease (n = 81), single-vessel disease (n = 35), and multi-vessel disease (n = 39) were 1.09, 1.15, and 1.19 with SDs of 0.16, 0.19, and 0.26, respectively. Those with an abnormal TID had a crude and adjusted odds ratio of 3.4 for multi-vessel disease which was statistically significant. History of diabetes was not found to be a significant confounder, effect modifier, or mediator of the relationship between the TID and the vessel disease. CONCLUSION: The mean TID ratio in patients with multi-vessel disease was 1.19. The threshold for an abnormal TID was 1.39 with specificity of 95% and sensitivity of 15% for determining multi-vessel CAD status. We conclude that the level of TID in gated SPECT MPI using regadenoson is associated with the degree of CAD on angiography.

Cryptogenic ischemic stroke and paradoxical embolism: should a patent foramen ovale be closed? Case report and literature review.

Paradoxical embolism is a well-recognized cause of stroke. While the diagnosis in the majority of the cases with a patent foramen ovale is presumptive, numerous treatment strategies have been described. However, there is no single approach that has been overwhelmingly recommended for these patients. A patient is described who presented with ischemic stroke. Transesophageal echocardiography revealed a thrombus that straddled a patent foramen ovale. Anticoagulation with intravenous heparin resulted in resolution of thrombus and neurologic deficit. The literature regarding diagnosis and treatment of paradoxical embolism in the presence of patent foramen ovale is reviewed.

Dipyridamole-induced ST-segment elevation indicative of transmural myocardial ischemia--a case report.

Dipyridamole nuclear myocardial perfusion test is a safe and effective alternative to exercise nuclear perfusion testing for detecting myocardial ischemia. It is the procedure of choice in selected patients who are unable to exercise adequately. Intravenous dipyridamole causes coronary vasodilation with resultant maldistribution and heterogeneity of coronary flow in the presence of significant coronary artery disease. True ischemia, causing symptoms or ST-segment depression, is uncommon, in part because there is no increase in myocardial oxygen demand. A patient in whom myocardial ischemia developed, manifested by ST-segment elevation, during dipyridamole stress testing is described. Scintigraphic images illustrated a myocardial perfusion defect, which was consistent with coronary angiographic findings. This case report addresses the importance of dipyridamole-induced ST-segment elevation, its correlation with angiographic findings, and the need for continued hemodynamic and electrocardiographic monitoring in patients following dipyridamole infusion.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva: disabling angina and syncope with noninterarterial courses case report of two patients.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva or the right coronary artery is a rare coronary anomaly. This anomaly has been associated with sudden cardiac death in younger patients, depending on its course relative to the pulmonary artery. The authors report this rare anomaly in two patients. It presented as unstable angina in the first patient with a septal course. In the second patient, it presented as syncope with an anterior free wall course and absent left circumflex artery. A septal course causing unstable angina has not been reported previously.

Anterior mitral valve aneurysm: a subaortic complication of aortic valve endocarditis: a case report and review of literature.

Mitral valve aneurysm is a rare cause of mitral regurgitation, and is usually associated with aortic valve endocarditis. Prompt diagnosis and early surgical treatment can prevent complications such as embolization and rupture of the aneurysm. The authors report a case of aortic valve endocarditis and mitral valve aneurysm in a patient who initially presented with urinary tract infection.

Percutaneous coronary intervention as a bridge to renal transplantation in a patient with end-stage renal disease--a case report.

Renal transplantation is one of the preferred modes of replacement therapy in patients with end-stage renal disease. Cardiovascular disease remains the leading cause of morbidity and mortality in patients with end-stage renal disease and renal transplant recipients. The authors describe a patient with end-stage renal disease who developed unstable angina before renal transplantation. Emergent cardiac catheterization and percutaneous coronary intervention served as a bridge to his successful renal transplantation without complications.

Ventricular septal defect and left ventricular aneurysm: late occurrence as complications of an acute myocardial infarction.

Mechanical complications of acute myocardial infarction (AMI) such as a ventricular septal defect (VSD) usually occur within the first week. In the thrombolytic era, the incidence of a VSD has not increased, but has been reported to occur earlier than previously described. We report an unusual case of an elderly Caucasian female with an acute anterior wall myocardial infarction treated with thrombolytic therapy. Her AMI was complicated by pulmonary edema secondary to a VSD and a left ventricular aneurysm five weeks later. Prompt diagnosis, immediate surgical closure of the VSD, and aneurysmectomy resulted in her complete recovery.

Recurrent right atrial thrombus after repair of ruptured sinus of valsalva aneurysm.

Ruptured sinus of Valsalva aneurysm is a rare cardiac abnormality. Early surgical repair is indicated to prevent complications such as heart failure, infective endocarditis, arrhythmias, and thromboembolic events. The authors report an unusual case of recurrent right atrial thrombus after the surgical repair and closure of ruptured sinus of Valsalva aneurysm.