Djeven P. Deva

Significance of left ventricular apical–basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

AIMS Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical-basal). METHODS AND RESULTS CMR was performed in 230 genotyped HCM patients (48 ± 15 years, 69% male), 30 genotype-positive/phenotype-negative (G+/P-) family members (32 ± 15 years, 30% male), and 126 controls. Left ventricular apical-basal muscle bundle was identified in 145 of 230 (63%) HCM patients, 18 of 30 (60%) G+/P- family members, and 12 of 126 (10%) controls (G+/P- vs. controls; P < 0.01). In HCM patients, the prevalence of an apical-basal muscle bundle was similar among those with disease-causing sarcomere mutations compared with patients without mutation (64 vs. 62%; P = 0.88). The presence of an LV apical-basal muscle bundle was not associated with LV outflow tract obstruction (P = 0.61). In follow-up, 33 patients underwent surgical myectomy of whom 22 (67%) were identified to have an accessory LV apical-basal muscle bundle, which was resected in all patients. CONCLUSION Apical-basal muscle bundles are a unique myocardial structure commonly present in HCM patients as well as in G+/P- family members and may represent an additional morphologic marker for HCM diagnosis in genotype-positive status.

Deep Basal inferoseptal crypts Occur More commonly in Patients with hypertrophic cardiomyopathy Due to Disease- causing Myofilament Mutations

PURPOSE To determine the relationship between deep basal inferoseptal crypts and disease-causing gene mutations in hypertrophic cardiomyopathy (HCM). MATERIALS AND METHODS Institutional research and ethics board approval was obtained for this retrospective study, and the requirement to obtain informed consent was waived. Two readers, who were blinded to genetic status, independently assessed cardiac magnetic resonance (MR) images obtained in 300 consecutive unrelated genetically tested patients with HCM. Readers documented the morphologic phenotype, the presence of deep basal inferoseptal crypts, and the imaging plane in which crypts were first convincingly visualized. The Student t test, the Fisher exact test, and multivariate logistic regression were used for comparisons and to evaluate the relationship between these crypts and the detection of disease-causing mutations. RESULTS The frequency of deep basal inferoseptal crypts was significantly higher in patients with disease-causing mutations than in those without disease-causing mutations (36% and 4%, respectively; P < .001). The presence of crypts was a stronger predictor of disease-causing mutations than was reverse septal curvature (P = .025). Patients with these crypts had a higher likelihood of having disease-causing mutations than non-disease-causing mutations (P < .001). Thirty-one of the 34 patients with both deep basal inferoseptal crypts and reverse septal curvature (91%) had disease-causing mutations (sensitivity, 26%; specificity, 98%). The presence of deep basal inferoseptal crypts (odds ratio: 6.64; 95% confidence interval: 2.631, 16.755; P < .001) and reverse septal curvature (odds ratio: 4.8; 95% confidence interval: 2.552, 9.083; P < .001) were predictive of disease-causing mutations. Both observers required additional imaging planes to identify approximately half of all crypts. CONCLUSION Deep basal inferoseptal crypts occur more commonly in patients with HCM with disease-causing mutations than in those with genotype-negative HCM.

Accuracy of Right and Left Ventricular Functional Assessment by Short-Axis vs Axial Cine Steady-State Free-Precession Magnetic Resonance Imaging: Intrapatient Correlation With Main Pulmonary Artery and Ascending Aorta Phase-Contrast Flow Measurements

Objective The left ventricle (LV) is routinely assessed with cardiac magnetic resonance imaging (MRI) by using short-axis orientation; it remains unclear whether the right ventricle (RV) can also be adequately assessed in this orientation or whether dedicated axial orientation is required. We used phase-contrast (PC) flow measurements in the main pulmonary artery (MPA) and the ascending aorta (Aorta) as nonvolumetric standard of reference and compared RV and LV volumes in short-axis and axial orientations. Methods A retrospective analysis identified 30 patients with cardiac MRI data sets. Patients underwent MRI (1.5 T or 3 T), with retrospectively gated cine steady-state free-precession in axial and short-axis orientations. PC flow analyses of MPA and Aorta were used as the reference measure of RV and LV output. Results There was a high linear correlation between MPA-PC flow and RV–stroke volume (SV) short axis (r = 0.9) and RV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 1.4 mL for RV axial and −2.3 mL for RV–short-axis vs MPA-PC flow. There was a high linear correlation between Aorta-PC flow and LV-SV short-axis (r = 0.9) and LV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 4.8 m for LV short axis and 7.0 mL for LV axial vs Aorta-PC flow. There was no significant difference (P = .6) between short-axis–LV SV and short-axis–RV SV. Conclusion No significant impact of the slice acquisition orientation for determination of RV and LV stroke volumes was found. Therefore, cardiac magnetic resonance workflow does not need to be extended by an axial data set for patients without complex cardiac disease for assessment of biventricular function and volumes.

Cardiovascular magnetic resonance demonstration of the spectrum of morphological phenotypes and patterns of myocardial scarring in Anderson-Fabry disease.

BackgroundAlthough it is known that Anderson-Fabry Disease (AFD) can mimic the morphologic manifestations of hypertrophic cardiomyopathy (HCM) on echocardiography, there is a lack of cardiovascular magnetic resonance (CMR) literature on this. There is limited information in the published literature on the distribution of myocardial fibrosis in patients with AFD, with scar reported principally in the basal inferolateral midwall.MethodsAll patients with confirmed AFD undergoing CMR at our center were included. Left ventricular (LV) volumes, wall thicknesses and scar were analyzed offline. Patients were categorized into 4 groups: 1) no wall thickening; 2) concentric hypertrophy; 3) asymmetric septal hypertrophy (ASH); and 4) apical hypertrophy. Charts were reviewed for clinical information.ResultsThirty-nine patients were included (20 males [51 %], median age 45.2 years [range 22.3–64.4]). Almost half (17/39) had concentric wall thickening. Almost half (17/39) had pathologic LV scar; three quarters of these (13/17) had typical inferolateral midwall scar. A quarter (9/39) had both concentric wall thickening and typical inferolateral scar. A subgroup with ASH and apical hypertrophy (n = 5) had greater maximum wall thickness, total LV scar, apical scar and mid-ventricular scar than those with concentric hypertrophy (n = 17, p < 0.05). Patients with elevated LVMI had more overall arrhythmia (p = 0.007) more ventricular arrhythmia (p = 0.007) and sustained ventricular tachycardia (p = 0.008).ConclusionsConcentric thickening and inferolateral mid-myocardial scar are the most common manifestations of AFD, but the spectrum includes cases morphologically identical to apical and ASH subtypes of HCM and these have more apical and mid-ventricular LV scar. Significant LVH is associated with ventricular arrhythmia.

The value of stress perfusion cardiovascular magnetic resonance imaging for patients referred from the adult congenital heart disease clinic: 5-year experience at the Toronto General Hospital

BACKGROUND Vasodilator stress perfusion cardiovascular magnetic resonance imaging is a clinically useful tool for detection of clinically significant myocardial ischaemia in adults. We report our 5-year retrospective experience with perfusion cardiovascular magnetic resonance in a large, quarternary adult congenital heart disease centre. METHODS We reviewed all cases of perfusion cardiovascular magnetic resonance in patients referred from the adult congenital heart disease service. Dipyridamole stress perfusion cardiovascular magnetic resonance was undertaken on commercially available 1.5 and 3 T cardiovascular magnetic resonance scanners. Late gadolinium enhancement imaging was performed 8-10 minutes after completion of the rest perfusion sequence. Navigator whole-heart coronary magnetic resonance angiography was also performed where feasible. RESULTS of stress cardiovascular magnetic resonance were correlated with complementary imaging studies, surgery, and clinical outcomes. RESULTS Over 5 years, we performed 34 stress perfusion cardiovascular magnetic resonance examinations (11 positive). In all, 84% of patients had further investigations for ischaemia in addition to cardiovascular magnetic resonance. Within a subgroup of 19 patients who had definitive alternative assessment of their coronary arteries, stress perfusion cardiovascular magnetic resonance demonstrated a sensitivity of 82% and specificity of 100%. Of the 34 studies, two were false negatives, in which the aetiology of ischaemia was extrinsic arterial compression rather than intrinsic coronary luminal narrowing. Coronary abnormalities were identified in 71% of cases who had coronary magnetic resonance angiography. CONCLUSION Stress perfusion cardiovascular magnetic resonance is a useful and accurate tool for investigation of myocardial ischaemia in an adult congenital heart disease population with suspected non-atherosclerotic coronary abnormalities.

Relationship between different blood pressure measurements and left ventricular mass by cardiac magnetic resonance imaging in end-stage renal disease.

Hypertension is prevalent in patients with end-stage renal disease and is strongly associated with left ventricular hypertrophy (LVH), an independent predictor of cardiovascular mortality. Blood pressure (BP) monitoring in hemodialysis patients may be unreliable because of its lability and variability. We compared different methods of BP measurement and their relationship with LVH on cardiac magnetic resonance imaging. Sixty patients undergoing chronic hemodialysis at a single dialysis center had BP recorded at each dialysis session over 12 weeks: pre-dialysis, initial dialysis, nadir during dialysis, and post-dialysis. Forty-five of these patients also underwent 44-hour inter-dialytic ambulatory BP monitoring. Left ventricular mass index (LVMI) was measured using cardiac magnetic resonance imaging and the presence of LVH was ascertained. Receiver operator characteristic curves were generated for each BP measurement for predicting LVH. The mean LVMI was 68 g/m(2) (SD = 15 g/m(2)); 13/60 patients (22%) had LVH. Mean arterial pressure measured shortly after initiation of dialysis session was most strongly correlated with LVMI (Pearson correlation coefficient r = 0.59, P < .0001). LVH was best predicted by post-dialysis systolic BP (area under the curve, 0.83; 95% confidence interval, 0.72-0.94) and initial dialysis systolic BP (area under the curve, 0.81; 95% confidence interval, 0.70-0.92). Forty-four-hour ambulatory BP and BP variability did not significantly predict LVH. Initial dialysis mean arterial pressure and systolic BP and post-dialysis systolic BP are the strongest predictors of LVH, and may represent the potentially best treatment targets in hemodialysis patients to prevent end-organ damage. Further studies are needed to confirm whether treatment targeting these BP measurements can optimize cardiovascular outcomes.

Optimal assessment of right ventricular function using cardiac magnetic resonance cine imaging after Mustard palliation for transposition of the great arteries.

Background The most common cause of a systemic right ventricle is atrial redirection surgery (Mustard repair) in the setting of complete TGA. Decreased RVEF is common and is a predictor of morbidity and mortality. Cardiac magnetic resonance (CMR) cine imaging is the reference standard for assessment of right heart size and function. However, the optimal method of RV planimetry using CMR in patients with Mustard palliation for complete TGA remains unclear.

Left Main Coronary Artery Compression Long Term After Repair of Conotruncal Lesions: The Bow String Conduit

We report 4 cases of left main coronary artery (LMCA) compression after remote repair of conotruncal lesions and their successful surgical management.

An unusual case of metastatic carcinoid tumour in the interventricular septum.

: Carcinoid heart disease is characterized by pulmonic and/or tricuspid valvular dysfunction and is the most common cardiac manifestation of carcinoid syndrome. We present an unusual cardiac manifestation of a rare entity carcinoid metastasis to the heart, without carcinoid heart disease. This rare case of carcinoid metastasis in the interventricular septum illustrates the utility of cardiac MRI in delineating the extent and tissue characteristics of the tumour, and its complementary role to nuclear scan.

Relationships Between Left Ventricular Structure and Function According to Cardiac MRI and Cardiac Biomarkers in End-Stage Renal Disease

BACKGROUND We sought to assess the relationships between left ventricular (LV) remodelling and the mechanical and uremic stressors in hemodialysis patients. METHODS In this prospective 2-centre cohort study, 67 prevalent hemodialysis patients were followed for 1 year. Data on routine bloodwork and predialysis blood pressure (BP) measurements were collected over a 12-week period. LV end-diastolic volume (LVEDV) and LV mass (LVM) were measured using cardiac magnetic resonance imaging and indexed. High-sensitivity troponin-I (hsTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), fibroblast growth factor 23 (FGF-23), and high-sensitivity C-reactive protein (hsCRP) were also measured. All study procedures were performed at baseline and at 1 year. We examined the relationships between LV remodelling and (1) NT-proBNP and hsTnI (LV stretch and injury); (2) ultrafiltration volume (UFV) and interdialytic weight gain (IDWT; volume overload); (3) predialysis BP measurements (pressure overload); and (4) biomarkers of inflammation (hsCRP) and fibrosis (FGF-23). RESULTS LVEDV was significantly associated with UFV and with IDWT, at baseline as well as at 1 year. NT-proBNP was significantly and negatively correlated with UFV and IDWT, respectively, at 1 year. There were significant correlations between systolic BP and LVM index, at baseline and at 1 year as well as longitudinally. Systolic BP was the only parameter longitudinally correlated with LVM/LVEDV. hsTnI was not associated with urea, parathyroid hormone, calcium, phosphorus, FGF-23, hsCRP, or hemoglobin. CONCLUSIONS We did not observe significant relationships between myocardial injury and markers of fibrosis, inflammation, and LV remodelling. Elevated predialysis systolic BP, which might represent a common mediator of pressure and volume overload, appears to be a dominant stimulus for LV remodelling.