Delayed contrast enhancement cardiac magnetic resonance imaging in trastuzumab induced cardiomyopathy

Background

Cardiac iron overload is the leading cause of death in thalassemia major and is usually assessed using myocardial T2* measurements. Recently a cardiovascular magnetic resonance (CMR) breath-hold T2 sequence has been developed as a possible alternative. This cardiac T2 technique has good interstudy reproducibility, but its transferability to different centres has not yet been investigated.

Methods and Results

The breath-hold black blood spin echo T2 sequence was installed and validated on 1.5T Siemens MR scanners at 4 different centres across the world. Using this sequence, 5–10 thalassemia patients from each centre were scanned twice locally within a week for local interstudy reproducibility (n = 34) and all were rescanned within one month at the standardization centre in London (intersite reproducibility). The local interstudy reproducibility (coefficient of variance) and mean difference were 4.4% and -0.06 ms. The intersite reproducibility and mean difference between scanners were 5.2% and -0.07 ms.

Conclusion

The breath-hold myocardial T2 technique is transferable between Siemens scanners with good intersite and local interstudy reproducibility. This technique may have value in the diagnosis and management of patients with iron overload conditions such as thalassemia.     

Stress echocardiography: abnormal response of tissue Doppler-derived indices to dobutamine in the absence of obstructive coronary artery disease in patients with chronic renal failure

BACKGROUND: Abnormal tissue Doppler (TD)-derived indices during dobutamine stress echocardiography (DSE) can predict the presence of coronary artery disease (CAD) in patients with normal renal function. These indices include a reduction in annular systolic velocity (S'), a decrease in early diastolic annular velocity (E'), and prolongation of the time to E'. However, the ability of these indices to detect or exclude CAD in patients with chronic renal failure (CRF) is unclear. OBJECTIVE: To examine the ability of TD-derived indices to detect or exclude the presence of CAD in patients with CRF. METHODS: We evaluated a total of 30 patients (13 males, mean age 57 +/- 15 years) using both DSE and coronary angiography. This cohort consisted of 12 control patients with normal renal function (mean creatinine 0.5 mg/dL) and 18 patient with CRF (mean creatinine 2.5 mg/dL). At each stage of the DSE, left ventricular (LV) diastolic function was assessed using conventional (peak early (E) and late (A) transmitral, E/A ratio, E-wave deceleration time (DT), and isovolumic relaxation time (IVRT)) and TD-derived indices (lateral annular systolic (S'), early diastolic (E'), and late atrial velocities (A'), time to E' and E/E'). RESULTS: All 30 patients had a normal DSE based on systolic regional function and a normal coronary angiogram. There was no difference in E, A, E/A, DT or IVRT between the two groups at each stage. Despite normal coronaries, patients with CRF demonstrated lower S' and E' velocities at peak stress compared to the control patients (8.0 +/- 2.2 cm/sec vs 15.1 +/- 2.6, P < 0.05 and 6.7 +/- 1.6 cm/sec vs 13.3 +/- 3.1, P < 0.05, respectively). During DSE, the time to E' at peak stress in CRF patients was also prolonged compared to control (400 +/- 44 ms vs 329 +/- 51, P < 0.05). Patients with CRF also had increased filling pressures (as estimated by E/E') as compared to controls at peak stress (14.7 +/- 5.2 vs 7.4 +/- 1.5, P < 0.05, respectively). CONCLUSION: In patients with CRF, a reduction in TD derived indices does not predict the presence of obstructive CAD.     

Necrotizing enterocolitis in a 16‐day‐old,term neonate

Necrotizing enterocolitis in a term neonate is a rare presentation to the ED. Prompt diagnosis and management is critical because of its rarity and the reported mortality of 5–20%. We report a case of necrotizing enterocolitis in a term neonate who presented at 16 days of age with bloody stool.     

Late gadolinium enhancement cardiovascular magnetic resonance in genotyped hypertrophic cardiomyopathy with normal phenotype

A 35 year-old asymptomatic Caucasian female with a family history of hypertrophic cardiomyopathy (HCM) was referred for cardiologic evaluation. The electrocardiogram and transthoracic echocardiogram were normal. Cardiovascular magnetic resonance (CMR) was performed for further assessment of myocardial function and presence of myocardial scar. CMR showed normal left ventricular systolic size, measurements and function. However, there was extensive, diffuse late gadolinium enhancement (LGE) throughout the left ventricle. This finding was consistent with extensive myocardial scarring and was highly suggestive of advanced, non-ischemic cardiomyopathy. Genotyping showed a heterozygous mis-sense mutation (275G>A) in the cardiac troponin T (TNNT2) gene, which is causally associated with HCM. There have been no previous reports of such extensive, atypical pattern of myocardial scarring despite an otherwise structurally and functionally normal left ventricle in an asymptomatic individual with HCM. This finding has important implications for phenotype screening in HCM.     

The Utility of Dobutamine Stress Echocardiography for the Diagnosis of Coronary Artery Disease in the HIV Population

Background: The introduction of highly active antiretroviral therapy (HAART) has increased human immunodeficiency virus (HIV) patient longevity by 10–15 years. This increased longevity has habituated new cardiovascular complications, in particular, accelerated coronary artery disease (CAD). Although dobutamine stress echocardiography (DSE) is a highly sensitive and specific test for the noninvasive detection of underlying CAD in the general population, its utility in the HIV population remains unknown. Objective: The objective of the current study was to assess the validity of DSE for the noninvasive detection of underlying symptomatic CAD in the HIV population using cardiac catheterization as the gold standard. Methods and results: A total of 40 HIV positive patients (mean 49 ± 8 years; 31 males) between 2006 and 2009 inclusively underwent routine DSE and coronary angiography. A positive stress echo with new wall motion abnormalities was detected in 9 (23%) individuals. Coronary angiography, following DSE, detected obstructive CAD in 12 (30%) individuals. For the diagnosis of obstructive CAD, DSE has a sensitivity of 67%, specificity of 97%, positive predictive value (PPV) of 89%, and negative predictive value (NPV) of 87%. Conclusion: In this select HIV population, DSE was highly specific for the noninvasive detection of obstructive CAD. (Echocardiography 2010;27:1228‐1232)     

Isolated pulmonic valve endocarditis

A 61-year-old man with no known cardiac history presented with septic arthritis of the right knee secondary to group B Streptococcus. During follow-up, echocardiography revealed a 1.8 cm x 1.2 cm mobile vegetation on the pulmonary valve. Despite parenteral antimicrobial therapy, the patient developed recurrent pulmonary emboli with enlargement of the vegetative mass, necessitating surgical debridement and replacement of the pulmonary valve. A diagnosis of pulmonic valve endocarditis should be considered in the differential diagnosis of any febrile patient with multiple pulmonary emboli.