Patients with hypertrophic cardiomyopathy (HC) are at increased risk of sudden cardiac death. Abnormalities in myocardial blood flow (MBF) detected by positron emission tomography (PET) are common in HC, but a PET marker that identifies patients at risk of sudden cardiac death is lacking. We hypothesized that disparities in regional myocardial perfusion detected by PET would identify patients with HC at risk of ventricular arrhythmias. To test this hypothesis, we quantified global and regional MBFs by NH-PET at rest and at stress, and developed a heterogeneity index to assess MBF heterogeneity in 133 symptomatic patients with HC. The MBF heterogeneity index was computed by dividing the highest by the lowest regional MBF value, at rest and after vasodilator stress, in each patient. High stress MBF heterogeneity was defined as an index of ≧1.85. Patients with HC were stratified by the presence or the absence of ventricular arrhythmias, defined as sustained ventricular tachycardia (VT) and/or nonsustained VT, during follow-up. We found that global and regional MBFs at rest and stress were similar in patients with HC with or without ventricular arrhythmias. Variability in regional stress MBF was observed in both groups, but the stress MBF heterogeneity index was significantly higher in patients with HC who developed ventricular arrhythmias (1.82 ± 0.77 vs 1.49 ± 0.25, p <0.001). A stress MBF heterogeneity index of ≧1.85 was an independent predictor of both sustained VT (hazard ratio 16.1, 95% confidence interval 3.2 to 80.3) and all-VT (sustained-VT + nonsustained VT: hazard ratio 3.7, 95% confidence interval 1.4 to 9.7). High heterogeneity of stress MBF, reflected by an MBF heterogeneity index of ≥1.85, is a PET biomarker for ventricular arrhythmias in symptomatic patients with HC.
Pulmonary agenesis is a rare congenital anomaly, the etiology of which is not clearly known. Other systemic comorbidities such as cardiovascular, gastrointestinal, musculoskeletal, and urogenital system anomalies can be observed in more than half of the patients. It is usually diagnosed during childhood. Diagnosis in adulthood is very rare. We present a case of pulmonary agenesis diagnosed in an adult.
Estimation of left ventricular (LV) mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE) is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.
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