Myocardial biopsy findings and gadolinium enhanced cardiovascular magnetic resonance in dilated cardiomyopathy

Additive prognostic value of red cell distribution width over late gadolinium enhancement on CMR in patients with non-ischemic dilated cardiomyopathy

Elevated red cell distribution width (RDW) and late gadolinium enhancement on cardiac magnetic resonance (LGE-CMR) are both poor prognostic factors. This study examined the relationship between RDW and LGE-CMR characteristics in patients with non-ischemic dilated cardiomyopathy (NICM), and investigated whether the additive prognostic value of RDW as an integrative systemic factor over LGE-CMR exists or not. A total of consecutive 378 patients who underwent CMR at two general hospitals in South Korea were retrospectively analyzed. The primary endpoint was a composite of all-cause death, hospitalizations due to worsening heart failure and major arrhythmic events. During a mean follow-up period of 40.8 months, 151 (39.9%) patients experienced primary endpoints. The RDW value was significantly higher in patients with LGE than in those without LGE (13.7 ± 1.5% vs. 13.3 ± 1.4%, p = 0.034), but it was not associated with the extent or distribution patterns of the LGE. Addition of RDW into the model with clinical risk factors and LGE-CMR characteristics led to a significant improvement in the prediction of worse outcomes (χ² increased from 73 to 82; p = 0.023). RDW could provide incremental predictive value for adverse clinical events beyond LGE-CMR data in NICM patients.

Updated clinical overview on cardiac laminopathies: an electrical and mechanical disease

Cardiac laminopathies, associated with mutations in the LMNA gene, encompass a wide spectrum of clinical manifestations, involving electrical and mechanical alterations of cardiomyocytes. Thus, dilated cardiomyopathy, bradyarrhythmias and atrial or ventricular tachyarrhythmias may occur in a number of combined phenotypes. Nowadays, some attempt has been made to identify clinical predictors for the most life-threatening complications of LMNA-associated heart disease, i.e. sudden cardiac death and end-stage heart failure. The goal of this manuscript is to combine the most recent evidences in an updated review to show the state-of-the-art of such a complex disease group. This is supposed to be the starting point to collect more data and design new ad hoc studies to identify clinically useful predictors to stratify risk in mutation carriers, including probands and their asymptomatic relatives.

Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis

The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE. LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer. The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function, including dilated cardiomyopathy, end-stage hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, and myocarditis, and those with diffuse left ventricular (LV) hypertrophy including HCM, cardiac amyloidosis and Anderson-Fabry disease. A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy/dysplasia, an enhancement of right ventricular (RV) wall with functional and morphological changes of RV becomes apparent. Finally, the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments.

High sensitivity of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens in hypertrophic cardiomyopathy

BACKGROUND

Myocardial scarring can be assessed by cardiac magnetic resonance imaging with late gadolinium enhancement and by endomyocardial biopsy. However, accuracy of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens remains unknown in hypertrophic cardiomyopathy. We investigated whether late gadolinium enhancement in the whole heart reflects microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy.

METHODS AND RESULTS

Twenty-one consecutive patients with hypertrophic cardiomyopathy who were examined both by cardiac magnetic resonance imaging and by endomyocardial biopsy were retrospectively studied. The right interventricular septum was the target site for endomyocardial biopsy in all patients. Late gadolinium enhancement in the ventricular septum had an excellent sensitivity (100%) with a low specificity (40%) for predicting microscopic myocardial scarring in biopsied specimens. The sensitivity of late gadolinium enhancement in the whole heart remained 100% with a specificity of 27% for predicting microscopic myocardial scarring in biopsied specimens. Quantitative assessments of fibrosis revealed that the extent of late gadolinium enhancement in the whole heart was the only independent variable related to the microscopic collagen fraction in biopsied specimens (β  =  0.59, 95% confident interval: 0.15 - 1.0, p  =  0.012).

CONCLUSIONS

Although there was a compromise in the specificity, the sensitivity of late gadolinium enhancement was excellent for prediction of microscopic myocardial scarring in hypertrophic cardiomyopathy. Moreover, the severity of late gadolinium enhancement was independently associated with the quantitative collagen fraction in biopsied specimens in hypertrophic cardiomyopathy. These findings indicate that late gadolinium enhancement can reflect both the presence and the extent of microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy.

CMR quantification of myocardial scar provides additive prognostic information in nonischemic cardiomyopathy

OBJECTIVES

This study sought to determine whether the extent of late gadolinium enhancement (LGE) can provide additive prognostic information in patients with a nonischemic dilated cardiomyopathy (NIDC) with an indication for implantable cardioverter-defibrillator (ICD) therapy for the primary prevention of sudden cardiac death (SCD).

BACKGROUND

Data suggest that the presence of LGE is a strong discriminator of events in patients with NIDC. Limited data exist on the role of LGE quantification.

METHODS

The extent of LGE and clinical follow-up were assessed in 162 patients with NIDC prior to ICD insertion for primary prevention of SCD. LGE extent was quantified using both the standard deviation-based (2-SD) method and the full-width half-maximum (FWHM) method.

RESULTS

We studied 162 patients with NIDC (65% male; mean age: 55 years; left ventricular ejection fraction [LVEF]: 26 ± 8%) and followed up for major adverse cardiac events (MACE), including cardiovascular death and appropriate ICD therapy, for a mean of 29 ± 18 months. Annual MACE rates were substantially higher in patients with LGE (24%) than in those without LGE (2%). By univariate association, the presence and the extent of LGE demonstrated the strongest associations with MACE (LGE presence, hazard ratio [HR]: 14.5 [95% confidence interval (CI): 6.1 to 32.6; p < 0.001]; LGE extent, HR: 1.15 per 1% increase in volume of LGE [95% CI: 1.12 to 1.18; p < 0.0001]). Multivariate analyses showed that LGE extent was the strongest predictor in the best overall model for MACE, and a 7-fold hazard was observed per 10% LGE extent after adjustments for patient age, sex, and LVEF (adjusted HR: 7.61; p < 0.0001). LGE quantitation by 2-SD and FWHM both demonstrated robust prognostic association, with the highest MACE rate observed in patients with LGE involving >6.1% of LV myocardium.

CONCLUSIONS

LGE extent may provide further risk stratification in patients with NIDC with a current indication for ICD implantation for the primary prevention of SCD. Strategic guidance on ICD therapy by cardiac magnetic resonance in patients with NIDC warrants further study.

Direct comparison of the diagnostic capability of cardiac magnetic resonance and endomyocardial biopsy in patients with heart failure

AIMS

The diagnostic performance of cardiac magnetic resonance (CMR) has not been compared with that of other imaging modalities. Therefore, this study investigated the diagnostic capabilities of CMR and endomyocardial biopsy (EMB) in patients with heart failure (HF).

METHODS AND RESULTS

We studied 136 patients with cardiomyopathy who underwent both CMR and EMB. Independent diagnoses were made according to the results of (i) CMR alone; (ii) EMB alone; (iii) clinical data plus echocardiogram; (iv) clinical data, echocardiogram, plus CMR; and (v) clinical data, echocardiogram, plus EMB. These diagnoses were then compared with the final diagnosis (gold standard) that was made using the complete clinical data, including EMB and CMR. The sensitivities of the diagnosis strategies of (i-v) relative to the final diagnosis were 67, 79, 86, 97, and 100%, respectively. CMR alone demonstrated better sensitivity for cardiac sarcoidosis and greater specificity for dilated cardiomyopathy than EMB alone. CMR also tended to show better sensitivity for hypertensive heart disease. There was no difference between the diagnostic capability of CMR and EMB for hypertrophic cardiomyopathy (HCM). However, CMR showed excellent sensitivity (100%) for apical and obstructive HCM, whereas EMB displayed better sensitivity for dilated HCM. Moreover, combined diagnosis with clinical data, echocardiogram, plus CMR achieved superior agreement with the final diagnosis in comparison with EMB alone.

CONCLUSION

Non-invasive CMR demonstrated excellent diagnostic capability for patients with HF and was as effective as or superior to EMB. In particular, the use of CMR in combination with clinical data unrelated to EMB may provide excellent diagnostic accuracy for HF.

Relationship of cardiac magnetic resonance imaging and myocardial biopsy in the evaluation of nonischemic cardiomyopathy

This study was performed to determine the relative role of cardiac magnetic resonance (CMR) imaging and endomyocardial biopsy (EMB) in the evaluation of cardiomyopathy. Sixty-six patients with a clinical diagnosis of nonischemic dilated cardiomyopathy or restrictive cardiomyopathy underwent both EMB and CMR imaging as part of their diagnostic evaluation. The authors retrospectively reviewed the results of these two methods to determine their diagnostic impact and congruency. CMR imaging provided data on cardiac anatomy, left ventricular volumes, mass, and function in 85% of the patients, uncovered fibrosis in 31%, myocardial ischemia in 7%, and fibrofatty infiltration in two patients. EMB provided the histologic findings of cardiomyocyte hypertrophy in 77% of patients and substantial interstitial fibrosis in 59%. Six patients had EMB-proven amyloid heart disease, which was detected by CMR imaging in two. CMR imaging showed patterns of late gadolinium enhancement supportive of infiltrative disease or inflammation in 6 patients with EMB-proven definite (n=3) or borderline (n=3) myocarditis, but failed to do so in two other patients with borderline and two with resolving myocarditis. At the present time, CMR imaging and EMB remain complementary procedures in the evaluation of cardiomyopathic conditions.

Relation of replacement fibrosis to left ventricular diastolic function in patients with dilated cardiomyopathy

BACKGROUND

Previous studies have shown that delayed hyperenhancement (HE) by cardiac magnetic resonance (CMR) is related to left ventricular (LV) stiffness in a variety of cardiac diseases. However, it is not known whether this relation is also present in dilated cardiomyopathy (DCM), in which replacement fibrosis is less extensive.

METHODS

Consecutive patients with DCM (n = 50, age 56 ± 13 years, 20 females) were studied with CMR and two-dimensional and Doppler echocardiography. CMR images with breath-hold segmented inversion-recovery sequence were acquired 10 minutes after an intravenous bolus of gadolinium. The scar tissue distribution and extent were calculated in the 17 LV segments. LV diastolic function was assessed using mitral inflow and tissue Doppler velocities at the septal and lateral sides of the mitral annulus.

RESULTS

The group had an ejection fraction of 30% ± 11% and left atrial volume of 103 ± 50 mL by CMR. HE was present in 31 patients with a mean scar burden of 4% ± 7.6%. Patients with DCM without HE had a significantly higher septal E/e' ratio than patients with scar (P = .05), and there was no significant correlation between deceleration time and extent of HE. Lateral late diastolic velocity (a') had a weak inverse relation with the number of segments with HE (r = -0.44, P = .005) and with scar burden (r = -0.31, P = .05).

CONCLUSION

Patients with DCM without HE have higher LV filling pressures than patients with HE. Our findings suggest that other factors influence LV stiffness to a larger extent than replacement fibrosis in this population.

Late gadolinium enhanced cardiovascular magnetic resonance of lamin A/C gene mutation related dilated cardiomyopathy

BACKGROUND

The purpose of this study was to identify early features of lamin A/C gene mutation related dilated cardiomyopathy (DCM) with cardiovascular magnetic resonance (CMR). We characterise myocardial and functional findings in carriers of lamin A/C mutation to facilitate the recognition of these patients using this method. We also investigated the connection between myocardial fibrosis and conduction abnormalities.

METHODS

Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium enhancement (LGE) and cine images were performed to evaluate myocardial fibrosis, regional wall motion, longitudinal myocardial function, global function and volumetry of both ventricles. The location, pattern and extent of enhancement in the left ventricle (LV) myocardium were visually estimated.

RESULTS

Patients had LV myocardial fibrosis in 88% of cases. Segmental wall motion abnormalities correlated strongly with the degree of enhancement. Myocardial enhancement was associated with conduction abnormalities. Sixty-nine percent of our asymptomatic or mildly symptomatic patients showed mild ventricular dilatation, systolic failure or both in global ventricular analysis. Decreased longitudinal systolic LV function was observed in 53% of patients.

CONCLUSIONS

Cardiac conduction abnormalities, mildly dilated LV and depressed systolic dysfunction are common in DCM caused by a lamin A/C gene mutation. However, other cardiac diseases may produce similar symptoms. CMR is an accurate tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy and may help to initiate early treatment in this malignant familiar form of DCM.

[The role of cardiovascular magnetic resonance imaging in the diagnosis and prognosis of patients with heart failure]

Cardiovascular magnetic resonance (CMR) imaging is a tomographic technique, which allows three-dimensional slice orientation without limitations from acoustic windows inherent to echocardiography. Further advantages of CMR are its high temporal and spatial resolution, its excellent soft tissue resolution and its high blood-to-tissue contrast. Cardiovascular magnetic resonance is currently the only imaging technique, which provides a comprehensive study of both structure and function of the heart as well as myocardial perfusion and viability. Moreover, post-processing of CMR images does not require any geometric assumptions as in echocardiography to determine ventricular dimensions. This is particularly important when evaluating ventricles of patients with chronic heart failure with severely altered morphology that may have regional variations in wall thickness and contractility at least in ischemic cardiomyopathy. The highly reproducible results of CMR imaging have turned this technique into a reference standard for the non-invasive assessment of ventricular dimensions, mass and function. In cases with indeterminate results of clinical, electrocardiographic and particularly echocardiographic findings CMR should be used early in the process of diagnosis of patients with heart failure. Not only can altered structure and degree of ventricular and valvular dysfunctions be accurately assessed but also regional perfusion deficits and/or myocardial scars are easily detected. For therapeutic and prognostic reasons a simple differentiation between ischemic and non-ischemic cardiomyopathy should be achieved as the first diagnostic step. In addition, the type and localization of the late gadolinium enhancement (LGE) phenomenon may aid in non-invasively differentiating the etiology of non-ischemic cardiomyopathy. CMR may also improve the assessment and extent of interventricular and intraventricular dyssynchrony in patients to be selected for cardiac resynchronization therapy (CRT). Lastly, the LGE phenomenon may provide independent prognostic information in patients with a CRT system implanted, as well as in patients with ischemic and non-ischemic cardiomyopathy. Thus, CMR imaging should be implemented early in the diagnostic process of patients with heart failure to significantly improve the speed and accuracy of diagnostic procedures, to control the effect of therapeutic measures, and to select patients with a limited prognosis by assessing the degree of ventricular dysfunction and the extent of myocardial scarring.

Comparison of global and regional abnormalities in 99mTc-sestamibi and cardiac magnetic resonance imaging in dilated cardiomyopathy

OBJECTIVE

The clinical relevance of perfusion defects and increased washout rate (WOR) in (99m)Tc-sestamibi (Tc MIBI) imaging has not been well characterized in dilated cardiomyopathy (DCM). We analyzed abnormalities in Tc MIBI imaging in relation to those in cardiac magnetic resonance (CMR) imaging.

METHODS AND RESULTS

Nineteen DCM patients underwent both Tc MIBI and CMR imaging. The perfusion defects and global and regional MIBI WORs were evaluated with planar and single photon emission computed tomography (SPECT) images. The left ventricular function and the delayed enhancement (DE) were estimated with the cine- and DE-mode CMR. In the DCM patients, the Tc MIBI SPECT showed perfusion defects in 65 segments of 14 patients. The global and regional Tc MIBI WORs were higher than those in 10 normal volunteers (19.4 +/- 9.1% vs. 11.7 +/- 6.8% in global and 13.8 +/- 8.6% vs. 9.6 +/- 8.2% in regional WORs; mean +/- SD, P < .01). The DE-mode CMR demonstrated DE in 103 segments of 14 patients. The severity of perfusion defects was correlated with the extent of DE (r = 0.71, P < .01). The regional Tc MIBI WOR was highest in the segments with perfusion defects or DE, but the Tc MIBI WOR in segments without them was also higher than that in the normal volunteers. There was a weak but significant negative correlation between the regional Tc MIBI WOR and wall thickening (r = -0.23, P < .01).

CONCLUSIONS

In DCM, the severity of perfusion defects and the increase in Tc MIBI WOR reflect the spread of myocardial fibrosis and/or scar. The increase in Tc MIBI WOR is potentially associated with regional dysfunction of LV wall.

Diffuse late gadolinium enhancement by cardiovascular magnetic resonance predicts significant intraventricular systolic dyssynchrony in patients with non-ischemic dilated cardiomyopathy

BACKGROUND

Left ventricular dyssynchrony and myocardial fibrosis are common findings in patients with nonischemic dilated cardiomyopathy (NDCM). The aim of this study was to investigate the association between myocardial fibrosis and intraventricular systolic dyssynchrony (DYS-sys) in patients with NDCM.

METHODS

Thirty-nine patients with NDCM and sinus rhythm were enrolled. Intraventricular DYS-sys was evaluated using Doppler tissue imaging, and cardiac fibrosis was assessed with cardiovascular magnetic resonance imaging with a 17-segment cardiac model. Each segment was graded on a 2-point scale (segmental fibrosis score): 0 = absence of late gadolinium enhancement, and 1 = presence of late gadolinium enhancement. A cardiac fibrosis index was calculated as 17/(17 - sum of fibrotic segments). Receiver operating characteristic analysis was performed to determine the utility of the cardiac fibrosis index to predict intraventricular systolic dyssynchrony.

RESULTS

Patients with DYS-sys had larger left atrial size (P = .004) and left ventricular end-systolic (P = .028) and end-diastolic (P = .034) volumes and lower tricuspid annular Doppler tissue imaging peak systolic velocities (P = .037) compared with patients without DYS-sys. A cardiac fibrosis index > or = 1.4 predicted significant DYS-sys with 92% sensitivity and 60% specificity (area under the receiver operating characteristic curve, 0.703; 95% confidence interval, 0.512-0.893; P = .035). Patients with cardiac fibrosis indexes > or = 1.4 (group 1) had larger left ventricular end-systolic (P = .044) and end-diastolic (P = .034) volumes than those with cardiac fibrosis indexes < 1.4 (group 2). Nine of 11 patients (82%) in group 1 and 6 of 28 patients (21%) in group 2 had significant DYS-sys (Pearson's chi(2) = 12.169, P < .0001). Logistic regression analysis revealed that cardiac fibrosis index > or = 1.4 (odds ratio, 11.2; 95% confidence interval, 1.72-71.4; P = .012) was an independent predictor of DYS-sys.

CONCLUSION

Patients with NDCM and prominent cardiac fibrosis have significant DYS-sys. The cardiac fibrosis index is a useful tool to predict DYS-sys.

Delayed enhancement magnetic resonance imaging is a significant prognostic factor in patients with non-ischemic cardiomyopathy

BACKGROUND

Delayed enhancement (DE) on cardiac magnetic resonance imaging (CMR) is a marker of myocardial fibrosis. The absence of DE in CMR is a predictor of left ventricular (LV) functional improvement in patients with non-ischemic cardiomyopathy (NICM), so in the present study it was investigated whether presence of DE has prognostic significance in patients with NICM at long-term follow-up.

METHODS AND RESULTS

The 79 patients (56.4+/-13.5 years, 48 males) with NICM (LV ejection fraction <35%, no significant coronary artery disease) were monitored for occurrence of cardiac events. CMR was performed to assess DE. Cardiac events were defined as rehospitalization (because of worsening of heart failure), cardiac transplantation or death. There were 37 patients without and 42 patients with DE. The mean follow-up duration was 19+/-10 months. There was 1 event (2.7%, 1 rehospitalization) in the DE (-) group, whereas 13 events (30.9%, 1 death, 1 transplantation, 11 rehospitalizations) occurred in the DE (+) group. The event-free survival was significantly longer in the DE (-) group than in the DE (+) group (38.9+/-1.0 vs 28.4+/-2.7 months, P<0.01). Multivariate regression analysis revealed that presence of DE was the most potent, independent predictor of cardiac events (hazard ratio 8.06, confidence interval 1.03+/-63.41, P<0.05).

CONCLUSIONS

The presence of DE in CMR is a significant predictor of future cardiac events in patients with NICM.

[Current indications for cardiac MR imaging]

MRI has acquired over the years a role in the evaluation of cardiovascular pathology especially with regards to its ability to assess right and left ventricular function and delayed postcontrast "viability" sequences. Current class I clinical indications include: viability for patients with ischemic cardiomyopathy and acute coronary syndrome, etiology and prognostic evaluation of non-ischemic cardiomyopathies including myocarditis and arrhytmogenic right ventricular cardiomyopathy, chronic pericarditis and cardiac masses, non-urgent aortic aneurysm and dissection, congenital cardiopathies: vascular malformations and follow-up after curative or palliative surgery. MRI provides a complete non operator dependent evaluation, and is particularly useful for follow-up since it may be repeated due to its absence of ionizing radiation

Shorter difference between myocardium and blood optimal inversion time suggests diffuse fibrosis in dilated cardiomyopathy

PURPOSE

To find evidence of diffuse fibrosis in dilated cardiomyopathy (DCM) patients by comparing measurements on clinical late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) studies between DCM and healthy subjects.

MATERIALS AND METHODS

LGE-CMR and the Look-Locker images from 20 DCM patients and 17 healthy controls were analyzed. Blood signal-to-noise ratio (SNR), myocardium SNR, and blood-to-myocardium contrast-to-noise ratio (CNR) were measured on the LGE-CMR images. The optimal inversion time (TI) to null blood and myocardium was determined on the Look-Locker images. The postcontrast T(1) was estimated using a phantom study that correlated optimal TI and heart rate to T(1).

RESULTS

The blood SNR was lower, myocardium SNR was higher, and the blood-to-myocardium CNR was lower (6.6 +/- 0.7 vs. 10.3 +/- 0.9, P = 0.004) on DCM LGE-CMR images as compared to controls. The blood-myocardium optimal TI difference (DeltaTI) was lower (38 +/- 2 msec vs. 55 +/- 3 msec, P < 0.001) in DCM, and the estimated blood-myocardium T(1) difference (DeltaT(1)) (116 +/- 6 msec vs. 152 +/- 8 msec, P = 0.001) was also lower.

CONCLUSION

DCM patients have reduced blood-myocardium DeltaTI and DeltaT(1), and lower CNR as compared to controls, suggesting the presence of diffuse fibrosis. This may impact the interpretation of LGE data.

Electrocardiographic and cardiac magnetic resonance imaging parameters as predictors of a worse outcome in patients with idiopathic dilated cardiomyopathy

Aims

Clinical parameters are weak predictors of outcome in patients with idiopathic dilated cardiomyopathy (IDC). We assessed the prognostic value of cardiac magnetic resonance (CMR) parameters in addition to conventional clinical and electrocardiographic characteristics.

Methods and results

One hundred and forty-one IDC patients were studied. QRS and QTc intervals were measured in 12-lead surface electrocardiogram. Patients were followed for median 1339 days, including 483 patient-years. The primary endpoint—cardiac death or sudden death—occurred in 25 (18%) patients, including 16 patients with cardiac death, 3 patients with sudden cardiac death (SCD), and 6 patients with ICD shock. Late gadolinium enhancement (LGE) was detected in 36 patients (26%). Kaplan–Meier survival analysis displayed QRS >110 ms (P = 0.010), the presence of LGE (P = 0.037), and diabetes mellitus (P < 0.001) as significant parameters for a worse outcome. Multivariable analysis revealed cardiac index (P < 0.001), right ventricular end-diastolic volume index (RVEDVI) (P = 0.006) derived from CMR imaging, the presence of diabetes mellitus (P = 0.006), and QRS >110 ms (P = 0.045) as significant predictors for the primary endpoint.

Conclusion

Cardiac index and RVEDVI derived from CMR imaging in addition to QRS duration >110 ms from conventional surface ECG and diabetes mellitus provide prognostic impact for cardiac death and SCD in patients with IDC.

Applications of cardiac magnetic resonance in electrophysiology

Contemporary methods for evaluation and treatment of arrhythmia are increasingly dependent upon characterization of the underlying myocardial substrate. Cardiovascular magnetic resonance offers unsurpassed soft tissue resolution capable of visualizing detailed cardiac anatomic features and intra-myocardial barriers to conduction. Non-invasive visualization of such anatomic detail has the potential to improve methods to diagnose, risk stratify, and treat patients with arrhythmia. This review describes a brief overview of the current knowledge on the applications of cardiac magnetic resonance for evaluation and treatment of patients with arrhythmia.

Role of cardiac magnetic resonance imaging in assessment of nonischemic cardiomyopathies

Diagnosis of nonischemic cardiomyopathy is a challenging process that influences patient morbidity and mortality. Currently, the well known World Health Organization classification has been revisited by an American Heart Association expert consensus panel. The contemporary classification is compatible with the rapid evolution in molecular genetics and evolving diagnostic tools such as cardiac magnetic resonance imaging (MRI). Magnetic resonance imaging is a robust diagnostic tool that offers various techniques to assess the function, morphology, perfusion, and scarring of myocardial tissue thus providing better understanding of the underlying causes of nonischemic cardiomyopathies. In this review, we discuss the current role of cardiac MRI in the evaluation of nonischemic cardiomyopathy, in the context of the current American Heart Association classification of these disorders.

Cardiac involvement in a female carrier of Duchenne muscular dystrophy

A 42 year-old female carrier of Duchenne muscular dystrophy (DMD) was referred with suspected subacute myocarditis and non-sustained ventricular tachycardia. Echochardiography and cardiac catheterization revealed severely reduced left ventricular function (LVF). Coronary artery disease was excluded. Cardiac magnetic resonance imaging showed transmural, intramural and subepicardial late gadolinium enhancement. Myocardial biopsy excluded viral infection and showed severe myopathic changes with abnormal expression of dystrophin and utrophin. Moleculargenetic analysis of the DMD gene revealed frameshift duplication of exon 2. The patient received conventional heart failure therapy, implantable cardioverter/defibrillator-implantation and prednisolone to attenuate cardiac degradation. 6 months later she had improved clinically though LVF was still severely reduced.

Usefulness of delayed enhancement magnetic resonance imaging to differentiate dilated phase of hypertrophic cardiomyopathy and dilated cardiomyopathy

BACKGROUND

The dilated phase of hypertrophic cardiomyopathy (HCM) has a poor prognosis. For correct recognition of such patients, we compared the findings in cardiac delayed enhancement (DE)-magnetic resonance imaging (MRI) between HCM and dilated cardiomyopathy (DCM) patients.

METHODS AND RESULTS

Sixty-five patients (HCM 39, DCM 26) underwent gadolinium-DTPA-enhanced MRI. The HCM patients were divided into those with preserved (HCM-P, n = 30) and those with impaired systolic function (HCM-I, n = 9). DE-MRI demonstrated focal or diffuse DE at the left ventricular (LV) wall in 60% of HCM-P and 100% of HCM-I, but in only 12% of DCM. The DE distributed mainly septal to the anterior wall of LV, but the DE volume against whole LV muscle volume was much larger in HCM-I than in HCM-P and DCM (4.1 +/- 6.1% in HCM-P, 14.6 +/- 11.9% in HCM-I, and 0.8 +/- 2.4% in DCM, means +/- SD, P < .05). In HCM, there were weak but significant correlations between DE volume, and LV end-diastolic volume and LV end-systolic volume. In HCM-P, the percent of length shortening in the segments with DE was lower than that without DE.

CONCLUSIONS

The HCM patients had more DE than the DCM patients, and DE volume correlated to lower global and local LV function. DE-MRI may be useful to evaluate myocardial damage in HCM patients, and to differentiate the dilated phase of HCM from DCM.

MRI to assess arrhythmia and cardiomyopathies: relationship to echocardiography

Cardiomyopathies are a group of diseases that are associated with myocardial dysfunction and/or arrhythmia due to abnormalities of the myocardium. Echocardiography is the most commonly used method for functional evaluation and classification of cardiomyopathy since it is widely available. Magnetic resonance imaging (MRI) has recently emerged as a well-validated diagnostic tool for the understanding and treatment of these conditions. Morphological and functional information can be achieved with a high level of accuracy and reproducibility. This article reviews the applications of MRI in relationship to echocardiography for the diagnosis of cardiomyopathy and arrhythmogenic conditions of the heart.

MRI to assess arrhythmia and cardiomyopathies

Cardiovascular magnetic resonance (CMR) is highly precise for morphological and functional analyses of the myocardium, and has been used to assess different types of cardiomyopathies. Its ability to characterize tissue, especially with gadolinium (Gd) delayed-enhancement techniques, has shown promising results for the diagnosis of arrhythmogenic cardiomyopathies. In this review we discuss the background and potential of this approach, as well as its usefulness for assessing arrhythmias and cardiomyopathies.