Major adverse events and atrial tachycardia in Ebstein's anomaly predicted by cardiovascular magnetic resonance.

OBJECTIVES: Patients with Ebstein's anomaly of the tricuspid valve (EA) are at risk of tachyarrhythmia, congestive heart failure and sudden cardiac death. We sought to determine the value of cardiovascular magnetic resonance (CMR) for predicting these outcomes. METHODS: Seventy-nine consecutive adult patients (aged 37±15 years) with unrepaired EA underwent CMR and were followed prospectively for a median 3.4 (range 0.4-10.9) years for clinical outcomes, namely major adverse cardiovascular events (MACEs: sustained ventricular tachycardia/heart failure hospital admission/cardiac transplantation/death) and first-onset atrial tachyarrhythmia (AT). RESULTS: CMR-derived variables associated with MACE (n=6) were right ventricular (RV) or left ventricular (LV) ejection fraction (EF) (HR 2.06, 95% CI 1.168 to 3.623, p=0.012 and HR 2.35, 95% CI 1.348 to 4.082, p=0.003, respectively), LV stroke volume index (HR 2.82, 95% CI 1.212 to 7.092, p=0.028) and cardiac index (HR 1.71, 95% CI 1.002 to 1.366, p=0.037); all remained significant when tested solely for mortality. History of AT (HR 11.16, 95% CI 1.30 to 95.81, p=0.028) and New York Heart Association class >2 (HR 7.66, 95% CI 1.54 to 38.20, p=0.013) were also associated with MACE; AT preceded all but one MACE, suggesting its potential role as an early marker of adverse outcome (p=0.011).CMR variables associated with first-onset AT (n=17; 21.5%) included RVEF (HR 1.55, 95% CI 1.103 to 2.160, p=0.011), total R/L volume index (HR 1.18, 95% CI 1.06 to 1.32, p=0.002), RV/LV end diastolic volume ratio (HR 1.55, 95% CI 1.14 to 2.10, p=0.005) and apical septal leaflet displacement/total LV septal length (HR 1.03, 95% CI 1.00 to 1.07, p=0.041); the latter two combined enhanced risk prediction (HR 6.12, 95% CI 1.67 to 22.56, p=0.007). CONCLUSION: CMR-derived indices carry prognostic information regarding MACE and first-onset AT among adults with unrepaired EA. CMR may be included in the periodic surveillance of these patients.

The shape and function of the right ventricle in Ebstein's anomaly.

BACKGROUND: Ebstein's anomaly involves both the right ventricle (RV) and tricuspid valve. METHODS: The functional RV and tricuspid orifice were traced from magnetic resonance images in 29 adult Ebstein patients and 9 normal subjects and reconstructed for visualization and measurement of regional RV size, function, and shape at 20 cross sections, and inlet and outflow tract ejection fractions (EFs). RESULTS: The RV in Ebstein's had RV dilation (end diastolic volume index 179 ± 69 vs. 84 ± 22 ml/m(2) in normals, p<0.001) and global dysfunction (EF 45 ± 8 vs. 55 ± 5% in normals, p<0.001). Longitudinal contraction was preserved (26 ± 13 vs. 26 ± 4 mm in normals) and correlated more weakly with EF than short axis fractional shortening (r=0.44 vs. r=0.71, p<0.05 for both). The apical region in Ebstein's RV was enlarged, rounded and contributed more than normal to the global stroke volume. However this contribution correlated inversely with global EF. In contrast slices in the basal region had normal cross sectional area and their function correlated directly with global EF. Inlet EF was depressed (46 ± 8% vs. 55 ± 6 in normals, p=.002); outflow tract EF was even more depressed (39 ± 14, p=0.019). CONCLUSION: The three dimensional shape of the RV in adult Ebstein patients was demonstrated. The Ebstein's RV remodels in diverse regional patterns rather than following a shape continuum. Changes at the apex and base had opposing effects on function. Global EF was supported more by short axis than longitudinal contraction.

Prognostic value of exercise echocardiography in patients with left bundle branch block.

OBJECTIVES: Our aim was to evaluate the role of exercise echocardiography for predicting outcome in a cohort of patients with left bundle branch block (LBBB). BACKGROUND: Although the prognostic value of exercise echocardiography has been well established in several subgroups of patients, it has not been specifically assessed in patients with LBBB. METHODS: Of the 8,050 patients who underwent treadmill exercise echocardiography, 618 demonstrated complete LBBB. Nine patients were lost to follow-up and 609 patients were included in this study. Wall motion score index (WMSI) was evaluated at rest and at peak exercise, and the difference (DeltaWMSI) was calculated. Ischemia was defined as the development of new or worsening wall motion abnormalities with exercise. End points were all-cause mortality and major cardiac events (including cardiac death, myocardial infarction, or cardiac transplantation). Mean follow-up was 4.6 +/- 3.4 years. RESULTS: Mean age was 66 +/- 10 years, and 331 patients (54%) were men. A total of 177 patients (29%) developed ischemia with exercise. During follow-up, 124 deaths occurred, and 74 patients had a major cardiac event before any revascularization procedure. Patients with ischemia had a greater 5-year mortality rate (24.6% vs. 12.6%, p < 0.001) and 5-year major cardiac events rate (18.1% vs. 9.7%, p = 0.003). In multivariate analysis, DeltaWMSI remained an independent predictor of mortality (hazard ratio: 2.42, 95% confidence interval: 1.21 to 4.82, p = 0.012) and major cardiac events (hazard ratio: 3.38, 95% confidence interval: 1.30 to 8.82, p = 0.013). Exercise echocardiographic results also provided incremental value over clinical, resting echocardiographic, and treadmill exercise data for the prediction of mortality (p = 0.014) and major cardiac events (p = 0.017). CONCLUSIONS: Exercise echocardiography provides significant prognostic information for predicting outcome in patients with LBBB. As compared to patients with normal exercise echocardiograms, patients with abnormal results are at increased risk of mortality and major cardiac events.

Ventrículo derecho pulmonar y sistémico / Right ventricle: systemic and pulmonary circulation

El ventrículo derecho está implicado con frecuencia en las cardiopatías congénitas, y la disfunción ventricular derecha es un factor determinante del pronóstico. La evaluación de la morfología, las dimensiones y la función del ventrículo derecho es de gran importancia en el manejo clínico de los pacientes, pero presenta limitaciones por la forma compleja del ventrículo y por su alta dependencia de las condiciones de carga. En los últimos años, y gracias al avance de técnicas de imagen como la ecocardiografía y, principalmente, la resonancia magnética cardiovascular, se ha profundizado en el estudio del ventrículo derecho y se ha mejorado en el conocimiento de su estructura y su función (AU)

Congenital heart disease often involves the right ventricle and right ventricular dysfunction is an important determinant of prognosis. Assessment of right ventricular morphology, size and function is of paramount importance for patient management but is hampered by the complex shape of the ventricle and by the strong influence of loading conditions. Development in imaging techniques, such as echocardiography and cardiovascular magnetic resonance, that have taken place in recent years have enabled more detailed study of the right ventricle and have increased our knowledge of its structure and function (AU)

Prognostic value of mitral regurgitation assessment during exercise echocardiography in patients with left ventricular dysfunction: a follow-up study of 1.7 +/- 1.5 years.

AIMS: The value of exercise echocardiography (EE) over resting echocardiography when this last incorporates information on mitral regurgitation (MR) is only partially known. Furthermore, limited data exist regarding the value of MR worsening during exercise in patients with left ventricular (LV) dysfunction. We investigate whether EE has incremental value over a resting echo-Doppler study; and whether post-exercise MR increments the value of EE for predicting outcome in patients with LV dysfunction. METHODS AND RESULTS: Three hundred and twenty-three consecutive patients with LV dysfunction (LV ejection fraction < or =45%) referred for EE were followed for 1.7 +/- 1.5 years. There were 43 hard events (myocardial infarction in 9 and cardiac death in 34). Resting MR, peak heart rate x blood pressure, and number of involved territories at exercise were independently associated to hard events (incremental P-value of EE =0.02). Independent variables associated to cardiac death were resting MR, peak heart rate x blood pressure, peak wall motion score index, and MR worsening (incremental P-value of MR worsening = 0.04). CONCLUSIONS: EE maintains its prognostic value over resting echocardiography even when this last incorporates information on MR. Exercise-induced MR worsening has independent prognostic value for cardiac death in patients with LV dysfunction.

Pulmonary arterial thrombosis in eisenmenger syndrome is associated with biventricular dysfunction and decreased pulmonary flow velocity.

OBJECTIVES: This study sought to determine what factors are associated with pulmonary artery thrombi in Eisenmenger patients. BACKGROUND: Pulmonary artery thrombosis is common in Eisenmenger syndrome, although its underlying pathophysiology is poorly understood. METHODS: Adult patients with Eisenmenger syndrome underwent computed tomography pulmonary angiography, cardiac magnetic resonance imaging, and echocardiography. Measurement of ventricular function, pulmonary artery size, and pulmonary artery blood flow were obtained. Hypercoagulability screening and platelet function assays were performed. RESULTS: Of 55 consecutive patients, 11 (20%) had a detectable thrombus. These patients were older (p = 0.032), but did not differ in oxygen saturation, hemoglobin, or hematocrit from those without thrombus. Right ventricular ejection fraction by magnetic resonance imaging was lower in those with thrombus (0.41 +/- 0.15 vs. 0.53 +/- 0.13, p = 0.017), as was left ventricular ejection fraction (0.48 +/- 0.12 vs. 0.60 +/- 0.09, p = 0.002), a finding corroborated by tissue Doppler and increased brain natriuretic peptide. Those with thrombus also had a larger main pulmonary artery diameter (48 +/- 14 mm vs. 38 +/- 9 mm, p = 0.007) and a lower peak systolic velocity in the pulmonary artery (p = 0.003). There were no differences in clotting factors, platelet function, or bronchial arteries between groups. Logistic regression showed pulmonary artery velocity to be independently associated with thrombosis. CONCLUSIONS: Pulmonary arterial thrombosis among adults with Eisenmenger syndrome is common and relates to older age, biventricular dysfunction, and slow pulmonary artery blood flow rather than degree of cyanosis or coagulation abnormalities. Further work to define treatment efficacy is needed.

[Reconstruction of the right ventricular outflow tract using a Medtronic Freestyle aortic root bioprosthesis]. / Reconstrucción del tracto de salida del ventrículo derecho con raíz aórtica protésica Medtronic Freestyle.

Uncorrected, long-term pulmonary regurgitation leads to right ventricular dilatation and dysfunction in a significant percentage of patients. We used magnetic resonance imaging (MRI) before and after surgery to assess the effect of pulmonary valve replacement with the Medtronic Freestyle bioprosthesis on right ventricular function and volume in nine patients with pulmonary regurgitation or stenosis. Mean follow-up time was 26 (10) months. We observed a decrease in mean end-diastolic volume from 143.6 (85.1) mL/m2 to 74.1 (12.6) mL/m2 (P=.018) and, in end-systolic volume from 88.0 (50.3) mL/m2 to 35.8 (19.3) mL/m2 (P=.016). In pulmonary valve disease, extensive follow-up by MRI is essential for timely evaluation of the degree of right ventricular dilation or dysfunction and for selecting a suitable time for valve replacement. The Medtronic Freestyle bioprosthesis is a good surgical choice for pulmonary valve replacement as its use is associated with low morbidity and mortality and the successful normalization of ventricular volumes.

Reconstrucción del tracto de salida del ventrículo derecho con raíz aórtica protésica Medtronic Freestyle / Reconstruction of the right ventricular outflow tract using a medtronic freestyle aortic root bioprosthesis

La insuficiencia pulmonar no corregida conduce a la dilatación y disfunción del ventrículo derecho a largo plazo en un porcentaje importante de pacientes. Hemos analizado mediante resonancia magnética cardiaca (RMC) preoperatoria y postoperatoria el efecto del recambio valvular pulmonar con prótesis Medtronic Freestyle en la función y los volúmenes del ventrículo derecho en 9 pacientes con insuficiencia y/o estenosis pulmonar con seguimiento de 26 ± 10 meses. Observamos una disminución del volumen telediastólico medio desde 143,6 ± 85,1 hasta 74,1 ± 12,6 ml/m2 (p = 0,018), y del volumen telesistólico medio desde 88 ± 50,3 hasta 35,8 ± 19,3 ml/m2 (p = 0,016). La valvulopatía pulmonar requiere un seguimiento exhaustivo mediante RMC para determinar precozmente el grado de dilatación y disfunción del ventrículo derecho, y así decidir el momento idóneo para la sustitución valvular. La bioprótesis Freestyle en posición pulmonar es una opción quirúrgica adecuada, con una baja morbimortalidad y excelentes resultados en cuanto a restauración volumétrica ventricular (AU)

Uncorrected, long-term pulmonary regurgitation leads to right ventricular dilatation and dysfunction in a significant percentage of patients. We used magnetic resonance imaging (MRI) before and after surgery to assess the effect of pulmonary valve replacement with the Medtronic Freestyle bioprosthesis on right ventricular function and volume in nine patients with pulmonary regurgitation or stenosis. Mean follow-up time was 26 (10) months. We observed a decrease in mean end-diastolic volume from 143.6 (85.1) mL/m2 to 74.1 (12.6) mL/m2 (P=.018) and, in end-systolic volume from 88.0 (50.3) mL/m2 to 35.8 (19.3) mL/m2 (P=.016). In pulmonary valve disease, extensive follow-up by MRI is essential for timely evaluation of the degree of right ventricular dilation or dysfunction and for selecting a suitable time for valve replacement. The Medtronic Freestyle bioprosthesis is a good surgical choice for pulmonary valve replacement as its use is associated with low morbidity and mortality and the successful normalization of ventricular volumes (AU)

Relation of left ventricular chamber stiffness at rest to exercise capacity in hypertrophic cardiomyopathy.

The degree of exercise capacity is poorly predicted by conventional markers of disease severity in patients with hypertrophic cardiomyopathy (HC). The principal mechanism of exercise intolerance in patients with HC is the failure of stroke volume augmentation due to left ventricular (LV) diastolic dysfunction. The role of LV chamber stiffness, assessed noninvasively, as a determinant of exercise tolerance is unknown. Sixty-four patients with HC were studied with Doppler echocardiography, exercise testing, and gadolinium cardiac magnetic resonance. The LV chamber stiffness index was determined as the ratio of pulmonary capillary wedge pressure (derived from the E/Ea ratio) to LV end-diastolic volume (assessed by cardiac magnetic resonance). Maximal exercise tolerance was defined as achieved METs. There were inverse correlations between METs achieved and age (r = -0.38, p = 0.003), heart rate deficit (r = -0.39, p = 0.002), LV outflow tract gradient (r = -0.33, p = 0.009), the E/Ea ratio (r = -0.4, p = 0.001), mean LV wall thickness (r = -0.26, p = 0.04), and LV stiffness (r = -0.56, p <0.001) and a positive correlation between METs achieved and LV end-diastolic volume (r = 0.33, p = 0.01). On multivariate analysis, only LV chamber stiffness was associated with exercise capacity. A LV stiffness level of 0.18 mm Hg/ml had 100% sensitivity and 75% specificity (area under the curve 0.84) for predicting < or =7 METs achieved. In conclusion, LV diastolic dysfunction at rest, as manifested by increased LV chamber stiffness, is a major determinant of maximal exercise capacity in patients with HC.

Risk stratification by treadmill exercise echocardiography in patients with excellent exercise capacity.

BACKGROUND: The incremental value of exercise echocardiography (EE) has been demonstrated to be maximal in patients with moderate pretest probability for coronary artery disease, but there is a lack of data in patients with low pretest probability or patients with good functional capacity. METHODS: To investigate whether such incremental value is maintained in patients with excellent exercise capacity, we studied 1,433 patients who had excellent exercise capacity (>or=8 METs for women, >or=10 METs for men). RESULTS: During a follow-up of 2.3 +/- 1.5 years, 42 hard events occurred (cardiac death or nonfatal myocardial infarction). Variables independently associated to hard events were male gender (P = 0.04), % of the age-predicted maximum heart rate (P = 0.02), chronotropic reserve (P = 0.002), and abnormal EE (P = 0.03; incremental P value of EE = 0.03). CONCLUSIONS: EE has incremental value over clinical variables, resting echocardiography, and exercise testing variables in patients with excellent exercise capacity. EE may be preferable to ECG exercise testing even in patients expected to have good exercise capacity.

[Value of resting and exercise mitral regurgitation during exercise echocardiography to predict outcome in patients with left ventricular dysfunction]. / Valor pronóstico de la regurgitación mitral en reposo y ejercicio durante la ecocardiografía de ejercicio en pacientes con disfunción ventricular izquierda.

INTRODUCTION AND OBJECTIVES: The relative value of exercise echocardiography (EE) over resting echocardiography when this last incorporates information on mitral regurgitation (MR) is unknown. Furthermore, limited data exists regarding to the value of MR worsening during exercise in patients with LV dysfunction. We investigated whether: a) EE has incremental value over a resting echo-Doppler study; and b) post-exercise MR increments the value of EE for predicting outcome in patients with LV dysfunction. METHODS: 388 consecutive patients with LV dysfunction (LV ejection fraction <50%) were followed for 2.1 (1.5) years. There were 46 hard events (myocardial infarction in 10 and cardiac death in 36). RESULTS: There were 43 events in 319 patients with abnormal EE vs 3 events in 69 patients with normal EE (13% vs 4%, P=.04), whereas there were 20 events in the 103 patients with at least moderate resting MR vs 26 events in the 288 with no/mild MR (19% vs 9%, P=.006). Resting MR, peak heart rate x blood pressure, and n masculine of diseased territories on EE were independently associated to hard events. The same variables and MR worsening were independently associated to cardiac death. CONCLUSIONS: EE maintains its higher prognostic value over resting echocardiography even when this last incorporates information on MR. MR worsening increments the value of EE for predicting cardiac death in patients with LV dysfunction.

Valor pronóstico de la regurgitación mitral en reposo y ejercicio durante la ecocardiografía de ejercicio en pacientes con disfunción ventricular izquierda / Value of resting and exercise mitral regurgitation during exercise echocardiography to predict outcome in patients with left ventricular dysfunction

Introducción y objetivos. El valor relativo de la ecocardiografía de ejercicio (EE) sobre la ecocardiografía basal cuando esta última incorpora información sobre la regurgitación mitral (RM) es desconocido. Además, hay poca información sobre el valor del empeoramiento de la RM durante el ejercicio en pacientes con disfunción ventricular. El objetivo fue investigar: a) si la EE incrementa el valor pronóstico de la ecocardiografía Doppler basal, y b) si la RM posterior al ejercicio incrementa el valor pronóstico de la EE en pacientes con disfunción ventricular. Métodos. Se realizó el seguimiento de un grupo de 388 pacientes consecutivos con disfunción ventricular durante 2,1 ± 1,5 años. Hubo 46 eventos (infarto de miocardio en 10 y muerte cardiaca en 36). Resultados. Hubo 43 eventos en 319 pacientes con EE anormal frente a 3 eventos en 69 pacientes con EE normal (el 13 frente al 4%; p = 0,04), mientras que hubo 20 eventos en 103 pacientes con RM ≥ moderada basal frente a 26 eventos en los 288 con RM ligera o sin RM (el 19 frente al 9%; p = 0,006). La RM basal, el doble producto pico y el número de territorios afectos en la EE estaban independientemente asociados con eventos. Las mismas variables junto con el empeoramiento de la RM estaban independientemente asociadas con muerte cardiaca. Conclusiones. La EE mantiene su valor pronóstico sobre la ecocardiografía basal incluso cuando ésta incorpora información sobre la RM en pacientes con disfunción ventricular. El empeoramiento de la RM aumenta el valor predictivo de la EE para muerte cardiaca en pacientes con disfunción ventricular

Introduction and objectives. The relative value of exercise echocardiography (EE) over resting echocardiography when this last incorporates information on mitral regurgitation (MR) is unknown. Furthermore, limited data exists regarding to the value of MR worsening during exercise in patients with LV dysfunction. We investigated whether: a) EE has incremental value over a resting echo-Doppler study; and b) post-exercise MR increments the value of EE for predicting outcome in patients with LV dysfunction. Methods. 388 consecutive patients with LV dysfunction (LV ejection fraction <50%) were followed for 2.1 (1.5) years. There were 46 hard events (myocardial infarction in 10 and cardiac death in 36). Results. There were 43 events in 319 patients with abnormal EE vs 3 events in 69 patients with normal EE (13% vs 4%, P=.04), whereas there were 20 events in the 103 patients with at least moderate resting MR vs 26 events in the 288 with no/mild MR (19% vs 9%, P=.006). Resting MR, peak heart rate x blood pressure, and nº of diseased territories on EE were independently associated to hard events. The same variables and MR worsening were independently associated to cardiac death. Conclusions. EE maintains its higher prognostic value over resting echocardiography even when this last incorporates information on MR. MR worsening increments the value of EE for predicting cardiac death in patients with LV dysfunction

[Clinical significance of late gadolinium enhancement on cardiovascular magnetic resonance in patients with hypertrophic cardiomyopathy]. / Significado clínico del realce tardío de gadolinio con resonancia magnética en pacientes con miocardiopatía hipertrófica.

INTRODUCTION AND OBJECTIVES: In patients with hypertrophic cardiomyopathy, myocardial fibrosis can be detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging. We investigated the relationships between the extent of LGE, left ventricular morphology and function, and clinical characteristics. METHODS: Both cine and gadolinium-enhanced magnetic resonance imaging were performed in 104 patients with hypertrophic cardiomyopathy. RESULTS: Fifty patients (48%) showed LGE (range: 1-11 segments). The extent of LGE was positively correlated with maximum left ventricular wall thickness (r=0.53, P< .001), left ventricular mass (r=0.41, P< .001), and the number of hypokinetic segments (r=0.51, P< .001), and inversely correlated with ejection fraction (r=-0.32, P=.001), the magnitude of the subaortic gradient increase during exercise echocardiography (r=-0.26, P=.023), and age at diagnosis (r=-0.20, P=.04). Four of the five patients with an ischemic response on exercise echocardiography had > or =3 segments showing LGE (P=.003). Severe hypertrophy (i.e., > or =30 mm) and nonsustained ventricular tachycardia occurred more frequently as the number of LGE segments increased (P< .001 and P=.04, respectively). CONCLUSIONS: Extensive LGE reflects greater disease expression. It is associated with more severe myocardial damage (i.e., a lower ejection fraction and a larger number of hypokinetic segments) and with adverse clinical characteristics (e.g., young age at diagnosis, severe hypertrophy, nonsustained ventricular tachycardia, and an ischemic response on exercise), suggesting that it may be closely linked to prognosis.

Significado clínico del realce tardío de gadolinio con resonancia magnética en pacientes con miocardiopatía hipertrófica / Clinical significance of late gadolinium enhancement on cardiovascular magnetic resonance in patients with hypertrophic cardiomyopathy

Introducción y objetivos. La fibrosis miocárdica puede ser detectada en la miocardiopatía hipertrófica (MCH) mediante resonancia magnética cardiaca (RM) con realce tardío de gadolinio (RT). Analizamos la relación entre la extensión del RT y la morfología y función del ventrículo izquierdo (VI) y los datos clínicos. Métodos. Estudiamos con RM a 104 pacientes diagnosticados de MCH. Se obtuvieron secuencias de cine-RM y secuencias de realce tardío. Resultados. Cincuenta pacientes presentaron RT (48%; rango: 1-11 segmentos). La extensión del RT se correlacionó positivamente con el grosor máximo (r = 0,53; p < 0,001), la masa (r = 0,41; p < 0,001) y el número de segmentos hipocinéticos (r = 0,51; p < 0,001) del ventrículo izquierdo, e inversamente con la fracción de eyección (r = -­0,32; p = 0,001), la capacidad de incrementar el gradiente subaórtico durante la ecocardiografía de ejercicio (r = ­-0,26; p = 0,023) y la edad en el momento del diagnóstico (r = ­-0,20; p = 0,04). Cuatro de los 5 pacientes con una respuesta isquémica en la ecocardiografía de ejercicio presentaron ≥ 3 segmentos con RT (p = 0,003). La hipertrofia severa (≥ 30 mm) y la taquicardia ventricular no sostenida (TVNS) se asociaron con la extensión del RT (p < 0,001 y p = 0,04, respectivamente). Conclusiones. La extensión del RT refleja una mayor expresión de esta enfermedad. Se asocia con un daño miocárdico más severo (menor fracción de eyección y mayor número de segmentos hipocinéticos) y con parámetros clínicos adversos (edad más joven en el momento del diagnóstico, hipertrofia severa, TVNS y respuesta isquémica al ejercicio), lo que indica que podría vincularse al pronóstico

Introduction and objectives. In patients with hypertrophic cardiomyopathy, myocardial fibrosis can be detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging. We investigated the relationships between the extent of LGE, left ventricular morphology and function, and clinical characteristics. Methods. Both cine and gadolinium-enhanced magnetic resonance imaging were performed in 104 patients with hypertrophic cardiomyopathy. Results. Fifty patients (48%) showed LGE (range: 1­11 segments). The extent of LGE was positively correlated with maximum left ventricular wall thickness (r=0.53, P<.001), left ventricular mass (r=0.41, P<.001), and the number of hypokinetic segments (r=0.51, P<.001), and inversely correlated with ejection fraction (r=-­0.32, P=.001), the magnitude of the subaortic gradient increase during exercise echocardiography (r=­-0.26, P=.023), and age at diagnosis (r=-­0.20, P=.04). Four of the five patients with an ischemic response on exercise echocardiography had ≥3 segments showing LGE (P=.003). Severe hypertrophy (i.e., ≥30 mm) and nonsustained ventricular tachycardia occurred more frequently as the number of LGE segments increased (P<.001 and P=.04, respectively). Conclusions. Extensive LGE reflects greater disease expression. It is associated with more severe myocardial damage (i.e., a lower ejection fraction and a larger number of hypokinetic segments) and with adverse clinical characteristics (e.g., young age at diagnosis, severe hypertrophy, nonsustained ventricular tachycardia, and an ischemic response on exercise), suggesting that it may be closely linked to prognosis