Usefulness of India ink artifact in steady-state free precession pulse sequences for detection and quantification of intramyocardial fat.

PURPOSE: In steady state free precession (SSFP) images acquired with a repetition time/echo time (TR/TE) ≈ 2, fat is surrounded by a black boundary, called "India Ink" artifact. Indian Ink artifact may improve detection of intramyocardial fat. Aims of this study were: (i) to assess the accuracy of SSFP technique for the detection of fat metaplasia in remote myocardial infarction (RMI); (ii) to evaluate the inter- and intraobserver reproducibility for the quantification of intramyocardial fat using SSFP and fast spin echo/short TI inversion recovery (FSE/STIR) techniques. MATERIALS AND METHODS: A total of 200 patients (age 64 ± 10 years) with RMI (>1000 days) underwent MRI using a 1.5 Tesla (T) scanner. SSFP images (with a TR/TE ≈2), FSE and STIR images were acquired in short and long axis views. Fat was detected in FSE/STIR and SSFP images and its extent manually measured . The inter- and intraobserver agreement for the quantification of fat metaplasia using both the SSFP image and the FSE images was evaluated. RESULTS: Left ventricle intramyocardial fat was detected in SSFP images of 95 patients (47.5%) and in FSE/STIR images of 84 patients (42%). A very good agreement was found using the SSFP technique between investigators. CONCLUSION: SSFP sequence with TR/TE=2 is a valuable technique for identifying and quantifying the presence of fat tissue within the left ventricle myocardium in RMI.

Right ventricular ischemic injury in patients with acute ST-segment elevation myocardial infarction: characterization with cardiovascular magnetic resonance.

BACKGROUND: Experimental data show that the right ventricle (RV) is more resistant to ischemia than the left ventricle. To date, limited data are available in humans because of the difficulty of discriminating reversible from irreversible ischemic damage. We sought to characterize RV ischemic injury in patients with reperfused myocardial infarction using cardiovascular magnetic resonance. METHODS AND RESULTS: In 3 tertiary centers, 242 consecutive patients with reperfused acute ST-segment elevation myocardial infarction were studied with cardiovascular magnetic resonance at 1 week and 4 months after myocardial infarction. T2-weighted and postcontrast cardiovascular magnetic resonance scans were used to depict myocardial edema and late gadolinium enhancement, respectively. Early after infarction, RV edema was common (51% of patients), often associated with late gadolinium enhancement (31% of patients). Remarkably, RV edema and late gadolinium enhancement were found in 33% and 12% of anterior left ventricular infarcts, respectively. Baseline regional and global RV functions were inversely related to the presence and extent of RV edema and RV late gadolinium enhancement. At follow-up, a significant decrease in frequency (25/242 patients; 10%) and extent of RV late gadolinium enhancement was observed (P<0.001). With the use of multivariable analysis, the presence of RV edema was an independent predictor of RV global function improvement during follow-up (ß-coefficient=0.221, P=0.003). CONCLUSIONS: Early postinfarction RV ischemic injury is common and is characterized by the presence of myocardial edema, late gadolinium enhancement, and functional abnormalities. RV injury is not limited to inferior infarcts but is commonly found in anterior infarcts as well. Cardiovascular magnetic resonance findings suggest reversibility of acute RV dysfunction with limited permanent myocardial damage at 4-month follow-up.

Myocardial blood flow and fibrosis in hypertrophic cardiomyopathy.

BACKGROUND: We investigated the relationship between myocardial blood flow (MBF), fibrosis, risk factors for sudden death, and clinical manifestations in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Sixty-two patients with HCM (45 men, overall mean age 47 ± 16 years), 15 acromegalic patients with left ventricular hypertrophy (9 man, overall mean age 47 ± 12 years), and 20 healthy subjects underwent cardiac magnetic resonance. Resting MBF was measured as the ratio between coronary sinus flow measured by phase-contrast technique and left ventricular mass. Myocardial fibrosis was evaluated by late gadolinium enhancement (LGE) technique. In HCM patients, MBF was significantly lower than in control subjects and acromegalic patients. Patients with LGE had lower MBF than those without it (0.46 ± 0.2 vs 0.66 ± 0.29 mL·min(-1)·g(-1); P < .005). Patients with ventricular tachycardia at Holter monitoring had lower MBF (0.4 ± 0.14 vs 0.6 ± 0.29 mL·min(-1)·g(-1); P < .04). Among patients with preserved systolic function, those in New York Heart Association (NYHA) functional class ≥II had lower MBF than those in NYHA functional class I (0.46 ± 0.2 vs 0.69 ± 0.3 mL·min(-1)·g(-1); P < .003). MBF was the only independent predictor of worse clinical status (NYHA ≥II; P = .01). CONCLUSIONS: In HCM patients low resting MBF is associated with the presence of fibrosis. MBF is a predictor of worse clinical status.

Different substrates of non-sustained ventricular tachycardia in post-infarction patients with and without left ventricular dilatation.

BACKGROUND: We investigated the relationship between nonsustained ventricular tachycardia (NSVT) and left ventricular (LV) dilatation, function, remodeling, and scar tissue extent in patients with previous myocardial infarction (MI). METHODS AND RESULTS: Eighty-two patients (ages 64+/-10 years) with first previous MI were referred for 24-hour electrocardiogram recording and cine and delayed enhancement (DE) cardiac magnetic resonance (CMR). LV volumes, ejection fraction, systolic wall thickening, sphericity index, and core and peri-infarctual areas of scar tissue by CMR were evaluated. LV dilatation was observed in 39 patients. Episodes of NSVT were recorded in 32 patients: 23 with LV dilatation and 9 without. In the entire population, NSVT was related to ejection fraction, LV volumes, LV mass, and sphericity index; end-systolic volume (P=.001) resulted in the only independent predictor at multivariate analysis. In patients without LV dilatation, the occurrence of NSVT was only positively related with percentage of contracting segments with DE (P=.008). Conversely, in patients with LV dilatation, increase in LV mass (P=.020) and end-systolic volume (P=.038) were independent predictors of NSVT. CONCLUSIONS: Necrotic and viable myocardium coexistence within the same wall segments predicted occurrence of NSVT in patients without LV dilatation, whereas LV mass and end-systolic volume were predictors of NSVT in those with LV dilatation.

Quantitative analysis of late gadolinium enhancement in hypertrophic cardiomyopathy.

BACKGROUND: Cardiovascular magnetic resonance (CMR) with the late gadolinium enhancement (LGE) technique allows the detection of myocardial fibrosis in Hypertrophic cardiomyopathy (HCM). The aim of this study was to compare different methods of automatic quantification of LGE in HCM patients. METHODS: Forty HCM patients (mean age 48 y, 30 males) and 20 normal subjects (mean age 38 y, 16 males) underwent CMR, and we compared 3 methods of quantification of LGE: 1) in the SD2 method a region of interest (ROI) was placed within the normal myocardium and enhanced myocardium was considered as having signal intensity >2 SD above the mean of ROI; 2) in the SD6 method enhanced myocardium was defined with a cut-off of 6 SD above mean of ROI; 3) in the RC method a ROI was placed in the background of image, a Rayleigh curve was created using the SD of that ROI and used as ideal curve of distribution of signal intensity of a perfectly nulled myocardium. The maximal signal intensity found in the Rayleigh curve was used as cut-off for enhanced myocardium. Parametric images depicting non enhanced and enhanced myocardium was created using each method. Three investigators assigned a score to each method by the comparison of the original LGE image to the respective parametric map generated. RESULTS: Patients with HCM had lower concordance between the measured curve of distribution of signal intensity and the Rayleigh curve than controls (63.7 +/- 12.3% vs 92.2 +/- 2.3%, p < 0.0001).A cut off of concordance < 82.9% had a 97.1% sensitivity and 92.3% specificity to distinguish HCM from controls. The RC method had higher score than the other methods. The average extent of enhanced myocardium measured by SD6 and Rayleigh curve method was not significant different but SD6 method showed underestimation of enhancement in 12% and overestimation in 5% of patients with HCM. CONCLUSIONS: Quantification of fibrosis in LGE images with a cut-off derived from the Rayleigh curve is more accurate than using a fixed cut-off.

High prevalence of cardiac hypertophy without detectable signs of fibrosis in patients with untreated active acromegaly: an in vivo study using magnetic resonance imaging.

OBJECTIVE: Left ventricular (LV) hypertrophy and myocardial fibrosis are considered the main pathological features of acromegalic cardiomyopathy. The aim of the study was to evaluate the proportion of LV hypertrophy and the presence of fibrosis in acromegalic cardiomyopathy in vivo using cardiac magnetic resonance (CMR). DESIGN AND PATIENTS: Fourteen consecutive patients (eight women, mean age 46 +/- 10 years) with untreated active acromegaly were submitted to two-dimensional (2D) colour Doppler and integrated backscatter (IBS) echocardiography and CMR. MEASUREMENTS: LV volume, mass and wall thickness and myocardial tissue characterization (IBS and CMR). RESULTS: On echocardiography: mean LV mass (LVM) and LVM index (LVMi) were 209 +/- 48 g and 110 +/- 24 g/m(2), respectively; hypertrophy was revealed in five patients (36%); abnormal diastolic function [evaluated by isovolumic relaxation time (IVRT) or early (E) to late or atrial (A) peak velocities (E/A ratio)] was found in four patients (29%). Systolic function evaluated by measuring LV ejection fraction (LVEF) was normal (mean 72 +/- 12%) in all patients. Six patients (43%) had increased IBS (mean 57.4 +/- 6.2%). On CMR: mean LVM and LVMi were 151 +/- 17 g and 76 +/- 9 g/m(2), respectively; 10 patients (72%) had LV hypertrophy. Contrastographic delayed hyperenhancement was absent in all patients; on the contrary, mild enhancement was revealed in one patient. Systolic function was normal in all patients (LVEF 67 +/- 11%). LVMi was not related to serum IGF-1 concentrations or the estimated duration of disease. CONCLUSIONS: CMR is considered to be the gold standard for evaluating cardiac hypertrophy, fibrosis and systolic function. Using CMR, 72% patients with untreated active acromegaly had LV hypertrophy, which was only detected in 36% patients by echocardiography. However, cardiac fibrosis was absent in all patients irrespective of the estimated duration of disease. Although a very small increase in collagen content (as suggested by increased cardiac reflectivity at IBS), not detectable by CMR, could not be ruled out, it is unlikely that it would significantly affect cardiac function.

Prognostic Role of Cardiac Magnetic Resonance in Arrhythmogenic Right Ventricular Cardiomyopathy.

We sought to evaluate the prognostic role of cardiac magnetic resonance (CMR) in patients with definite, borderline and possible diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) as defined by the International Task Force (TF) in 2010. CMR was performed in 175 patients: 52 with definite, 50 with borderline and 73 possible ARVC. Abnormal-CMR was defined as the presence of ≥1 CMR abnormalities (including abnormalities of right ventricular and left ventricular wall motion, fat infiltration, late gadolinium enhancement, dilation and dysfunction of either ventricles). During the follow-up time 35 patients had hard cardiac events (sudden cardiac death, appropriate implantable cardioverter defibrillator shock and resuscitated cardiac arrest), and 34 of them occurred in patients with abnormal-CMR (negative predictive value = 96.9%). At the multivariate Cox-regression analysis LV involvement at CMR (fat infiltration and/or late gadolinium enhancement), and episode of nonsustained ventricular tachycardia (NSVT) were independent predictors of cardiac events in both the whole population (LV involvement: HR 3.69, 95% CI 1.57-8.65, p = 0.0002; NSVT: HR 5.8, 95% CI 2.82-11.9, p < 0.0001), and in the group of patients with definite ARVC (LV involvement: HR 3.03, 95% CI 1.15 to 8.02, p = 0.02; NSVT: HR 12.1, 95% CI 4.02-36.5, p < 0.0001). In conclusion, CMR evidence of LV involvement is a strong independent predictor of cardiac events in patients with definite, borderline or possible ARVC diagnosis. Abnormal CMR has very high negative predictive value for hard cardiac events.

Relation of pain-to-balloon time and myocardial infarct size in patients transferred for primary percutaneous coronary intervention.

The paradigm of a shorter pain-to-balloon time decreasing extent of infarct size may be not completely true in transferred patients. This study evaluated the influence of pain-to-balloon time on infarct size as assessed by delayed enhancement magnetic resonance imaging in patients transferred from a peripheral hospital to a tertiary center for primary coronary angioplasty (percutaneous coronary intervention [PCI]). Sixty patients (40 men, 64 +/- 3 years of age) with first acute myocardial infarction were treated within <168, 168 to 222, 223 to 300, and >300 minutes. A presentation score system including clinical, laboratory, and echocardiographic data was used to classify severity of presentation at admission. Magnetic resonance imaging was performed 6 +/- 3 days after PCI. Group 1 had a higher presentation score than did group 2 (p <0.02) and group 3 (p <0.02). Group 1 had a significantly longer delayed enhancement than did group 2 (p <0.002) and group 3 (p <0.03). In conclusion we found that patients with worse presentation are transferred sooner for primary PCI. This approach in these patients does not decrease infarct size likely because of unavoidable delay to reperfusion. This finding suggests a different therapeutic strategy in these patients.

Prognostic role of isolated left ventricular diverticuli detected by cardiovascular magnetic resonance.

BACKGROUND: Isolated left ventricular diverticulum, a rare cardiac malformation, can be asymptomatic or associated with systemic embolization, ventricular arrhythmias, or sudden death. MRI allows for the detection of diverticuli and the distinction between fibrous and muscular types using the delayed enhancement technique. AIM: To evaluate the prevalence of left ventricular diverticuli in nonselected consecutive patients who had undergone MRI. METHODS: In a total of 3273 consecutive patients who had undergone cardiac magnetic resonance from January 2001 to December 2005, isolated ventricular diverticuli were found in 25 patients (0.76%), with no apparent cardiac disease. A delayed enhancement technique was used to distinguish fibrous and muscular types. The prevalence of complications was evaluated with a follow-up of 52 ±â€Š8 months. RESULTS: The site of the left ventricular diverticuli was the septum in 10 (37%) cases, inferior wall in 6 (22%) cases, lateral wall in 4 (15%) cases, and apical in 7 (26%) cases. In two cases, multiple diverticuli were found. In delayed enhancement images, a partial or total fibrous diverticulum was found in 6 (24%) patients. At follow-up, clinical complications were recorded in 6 (24%) patients; 2 (8%) patients had arrhythmic complications and 4 (12%) patients had embolic complications of presumed cardiac origin. In addition, two patients (8%) had nonsustained ventricular tachycardia diagnosed using 24-h ECG Holter monitoring. Fibrous type diverticuli were associated with a higher incidence of arrhythmic complications than the muscular type. CONCLUSION: The prevalence of isolated ventricular diverticuli detected by MRI is higher than that previously reported with other imaging techniques. Fibrous diverticuli are associated with a higher incidence of arrhythmic complications.

Fat in left ventricular myocardium assessed by steady-state free precession pulse sequences.

Intramyocardial fat can be observed in different pathologic processes including arrhythmogenic right ventricular cardiomyopathy (ARVC) and in old myocardial infarction (OMI) In SSFP images, fat is hyperintense and surrounded by a black boundary, called "Indian Ink" artifact that is generated when fat and water coexist in the same voxel. Aim of this study was to compare the SSFP with the conventional FSE and STIR (FSE/STIR) method for the detection of LV intramyocardial fat. Fifty-four consecutive patients with OMI (>1,000 days) and 69 patients with a diagnosis of ARVC underwent magnetic resonance. LV fat was detected in 29 patients (53.7%) in SSFP images and in 28 patients (51.9%) in FSE/STIR images. At Bland- Altman plot a close agreement was found between the extent of fat measured in SSFP images and in FSE images. However, a slight systematic overestimation, was found for the fat quantification in the SSFP images. In the ARVC group, both FSE/STIR and SSFP images evidenced fat infiltration in LV myocardium in 11 patients (15.9%) without any mismatch. SSFP had 100% sensitivity and 98.8% of specificity to detect LV intramyocardial fat in ARVC and in ischemic heart disease. SSFP sequence with TR/TE = 2 is capable in identifying and quantifying the presence of fat tissue within the LV myocardium in patients with previous myocardial infarction and ARVC.

Impact of early abciximab administration on infarct size in patients with ST-elevation myocardial infarction.

BACKGROUND: Early abciximab administration in patients requiring transportation to undergo primary percutaneous coronary intervention (PPCI) has been reported to improve clinical outcome. We aimed to verify whether early administration leads to reduced infarct size (IS), assessed by delayed-enhancement magnetic resonance imaging (DE-MRI). METHODS: We randomized 110 patients with acute myocardial infarction with symptom-to-diagnosis time <6h to either early (55 patients) or late (55 patients) abciximab administration. DE-MRI was performed at 4 days and 6 months. The primary end point was IS at 6 months. Secondary end points were the rate of ST-segment elevation resolution ≥ 50% (STR) at 60 min after PPCI, the extent of microvascular obstruction at 4 days, and the change in IS and transmurality at 6 months vs. 4 days. RESULTS: DE-MRI was performed in 103 patients after 4 days, and in 87 at 6 months. The mean IS at 6 months was 13.8 ± 9.0% in the early vs. 13.0 ± 9.9% in the Late group (P>0.2). Similarly, microvascular obstruction and the change in IS were not significantly different. The Early group showed a significantly higher STR (94.5% vs. 80.0%, P=0.04) and a larger reduction in infarct transmurality (-9.2 ± 7.0% vs. -5.9 ± 6.4%; P=0.03), while a larger reduction in IS was observed only in patients with ECG-to-Cath Lab time >60 min. CONCLUSIONS: Early abciximab administration did not lead to a smaller IS at 6-month DE-MRI, and was associated with a significant reduction in IS and transmurality only in patients with longer transportation time, warranting further investigation in this patient subset.

Progression of myocardial fibrosis assessed with cardiac magnetic resonance in hypertrophic cardiomyopathy.

OBJECTIVES: This study sought to assess the rate of progression of fibrosis by 2 consecutive cardiac magnetic resonance (CMR) examinations and its relation with clinical variables. BACKGROUND: In hypertrophic cardiomyopathy (HCM) myocardial fibrosis, detected by late gadolinium enhancement (LGE), is associated to a progressive ventricular dysfunction and worse prognosis. METHODS: A total of 55 HCM patients (37 males; mean age 43 ± 18 years) underwent 2 CMR examinations (CMR-1 and CMR-2) separated by an interval of 719 ± 410 days. Extent of LGE was measured, and the rate of progression of LGE (LGE-rate) was calculated as the ratio between the increment of LGE (in grams) and the time (months) between the CMR examinations. RESULTS: At CMR-1, LGE was detected in 45 subjects, with an extent of 13.3 ± 15.2 g. At CMR-2, 53 (96.4%) patients had LGE, with an extent of 24.6 ± 27.5 g. In 44 patients, LGE extent increased significantly (≥1 g). Patients with apical HCM had higher increments of LGE (p = 0.004) and LGE-rate (p < 0.001) than those with other patterns of hypertrophy. The extent of LGE at CMR-1 and the apical pattern of hypertrophy were independent predictors of the increment of LGE. Patients with worsened New York Heart Association functional class presented higher increase of LGE (p = 0.031) and LGE-rate (p < 0.05) than those with preserved functional status. CONCLUSIONS: Myocardial fibrosis in HCM is a progressive and fast phenomenon. LGE increment, related to a worse clinical status, is more extensive in apical hypertrophy than in other patterns.

Cardiac magnetic resonance predicts outcome in patients with premature ventricular complexes of left bundle branch block morphology.

OBJECTIVES: We investigated whether the presence of right ventricular (RV) abnormalities detected by cardiovascular magnetic resonance (CMR) predict adverse outcome in patients presenting with frequent premature ventricular complexes (PVCs) of left bundle branch block (LBBB) morphology. BACKGROUND: CMR is a component of the diagnostic workup for the differential diagnosis between arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and idiopathic RV tachycardia. RV abnormalities evaluated by CMR could have prognostic importance. METHODS: Four hundred forty consecutive patients with >1,000 PVCs of LBBB morphology (minor diagnostic criterion of ARVC/D) and no other pre-existing criteria were prospectively enrolled. RV wall motion (WM), signal abnormalities, dilation, and reduced ejection fraction evaluated by CMR were considered imaging criteria of ARVC/D. Follow-up was performed evaluating an index composite end point of 3 cardiac events: cardiac death, resuscitated cardiac arrest, and appropriate implantable cardiac-defibrillator shock. RESULTS: Subjects with multiple RV abnormalities (RVA-2 group) had worse outcome than the no-RVA group (hazard ratio [HR]: 48.6; 95% confidence interval [CI]: 6.1 to 384.8; p < 0.001). Of the 61 patients in the RVA-2 group, only 6 had a definite diagnosis of ARVC/D applying the Task Force Criteria. Also, subjects with a single imaging criterion (RVA-1 group) had worse outcome than the no-RVA group (HR: 18.2; 95% CI: 2.0 to 162.6; p = 0.01). Patients with only WM abnormalities had higher prevalence of cardiac events than no-RVA (HR: 27.2; 95% CI: 3.0 to 244.0; p = 0.03). CONCLUSIONS: In subjects with frequent PVC of LBBB morphology, CMR allows risk stratification. RV abnormalities were associated with worse outcome.

Usefulness of delayed enhancement by magnetic resonance imaging in hypertrophic cardiomyopathy as a marker of disease and its severity.

The aim of the present study was to evaluate, in patients with hypertrophic cardiomyopathy (HC), the association between late gadolinium enhancement and clinical end points, such as nonsustained ventricular tachycardia, arrhythmic risk factors, New York Heart Association class, symptoms, and left ventricular functional parameters. A total of 20 normal subjects (mean age 38 years, 16 men) and 100 patients with HC (mean age 46 years, 70 men) were enrolled in the present study. In the late gadolinium enhancement images, the extent of unenhanced, mildly enhanced, and higher enhanced myocardium was measured. Higher enhancement was present in 80% of the HC population and was significantly greater in patients with a New York Heart Association class >1. Mild enhancement was present in all the patients with HC. Receiver operating characteristic analysis revealed that a cutoff of >4.9% of mild enhancement had 100% sensitivity and 86% specificity to predict the occurrence of nonsustained ventricular tachycardia, and a cutoff of >2.4% of hyperenhancement had 77% sensitivity and 96% specificity. In conclusion, late gadolinium enhancement was associated with nonsustained ventricular tachycardia, arrhythmic risk factors, and worse New York Heart Association class.

Myocardial salvage by CMR correlates with LV remodeling and early ST-segment resolution in acute myocardial infarction.

OBJECTIVES: The purpose of this study was to assess the association of myocardial salvage by cardiac magnetic resonance (CMR) with left ventricular (LV) remodeling and early ST-segment resolution in patients with acute myocardial infarction (MI). BACKGROUND: Experimental studies revealed that MI size is strongly influenced by the extent of the area at risk (AAR), limiting its accuracy as a marker of reperfusion treatment efficacy in acute MI studies. Hence, an index correcting MI size for AAR extent is warranted. T2-weighted CMR and delayed-enhancement CMR, respectively, enable the determination of AAR and MI size, and the myocardial salvage index (MSI) is calculated by correcting MI size for AAR extent. Nevertheless, the clinical value of CMR-derived MSI has not been evaluated yet. METHODS: In a prospective cohort of 137 consecutive patients with acutely reperfused ST-segment elevation MI, CMR was performed at 1 week and 4 months. T2-weighted CMR was used to quantify AAR, whereas MI size was detected by delayed-enhancement imaging. MSI was defined as AAR extent minus MI size divided by AAR extent. Adverse LV remodeling was defined as an increase in LV end-systolic volume of >or=15%. The degree of ST-segment resolution 1 h after reperfusion was also calculated. RESULTS: AAR extent was consistently larger than MI size (32+/-15% of LV vs. 18+/-13% of LV, p<0.0001), yielding an MSI of 0.46+/-0.24. MI size was closely related to AAR extent (r=0.81, p<0.0001). After correction for the main baseline characteristics by multivariate analyses, MSI was a major and independent determinant of adverse LV remodeling (odds ratio: 0.64; 95% confidence interval: 0.49 to 0.84, p=0.001) and was independently associated with early ST-segment resolution (B coefficient=0.61, p<0.0001). CONCLUSIONS: In patients with reperfused ST-segment elevation MI, CMR-derived MSI is independently associated with adverse LV remodeling and early ST-segment resolution, opening new perspectives on its use in studies testing novel reperfusion strategies.

Simultaneous visualization of myocardial scar, no-reflow phenomenon, ventricular and atrial thrombi by cardiac magnetic resonance.

The recognition of complications during acute phase of myocardial infarction remains a difficult dilemma. We report a cases where cardiac magnetic resonance was able to identify scar tissue, large no-reflow phenomenon, pericardial effusion and ventricular and atrial thrombi.

Cardiac magnetic resonance findings in isolated congenital left ventricular diverticuli.

Congenital ventricular diverticulum is a rare cardiac abnormality, frequently associated with other cardiac or non-cardiac congenital malformations. Clinically, congenital ventricular diverticulum may be asymptomatic or cause systemic embolization, heart failure, ventricular rupture, ventricular arrhythmia and sudden death. Cardiac magnetic resonance (CMR) can be a useful non-invasive and non-ionizing method to confirm the presence, size and extent of left ventricular (LV) diverticulum and its tissue characterization. In these reports we documented the presence of six diverticuli in patients underwent to CMR for other clinical indications. In all the cases, magnetic resonance showed an accurate assessment of diverticuli.

The obesity paradox and myocardial infarct size.

OBJECTIVE: Obese subjects have a risk of death from cardiovascular disease higher than those with normal body weight. Obese patients, however, have a better outcome when undergoing coronary revascularisation, and when suffering from heart failure or chronic kidney disease. The term 'obesity paradox' underlines the divergence between increased risk and better outcome in sick obese patients. We tested the hypothesis that the obesity paradox could also occur in myocardial infarction. METHODS: A group of 89 patients (mean age 62 +/- 11 years) with previous myocardial infarction (Q-wave in 72 patients) underwent contrast-enhanced MRI. RESULTS: Areas of delayed contrast enhancement (which reflects myocardial necrosis) were present in 15 +/- 9% of left ventricular myocardium. Infarct size was not influenced by patient age, gender, history of arterial hypertension, hypercholesterolaemia, hypertriglyceridaemia nor tobacco smoking. Infarct size, however, was larger in insulin-dependent diabetic patients (P = 0.06) and in those with a family history of premature coronary artery disease (P = 0.06). Surprisingly, infarct size was smaller in obese patients (11 +/- 4% of left ventricular myocardium) than in those with normal body weight (16 +/- 9% of left ventricular myocardium, P = 0.03). Insulin-dependent diabetes mellitus, obesity and family history of coronary artery disease were the only independent predictors of infarct size at multiple linear regression analysis. CONCLUSIONS: Owing to its limitations (small sample size and exclusion of extremely obese patients), this study generates a working hypothesis, which should be tested in larger prospective studies, that the obesity paradox could also occur in myocardial infarction.

Do mechanical markers of myocardial ischaemia predict the transmural extent of myocardial infarction in man?

BACKGROUND: The present study aimed to explore the relationship between the transmural extent of myocardial necrosis and mechanical markers of myocardial ischaemia in man. METHODS: A group of 40 patients with previous Q-wave myocardial infarction and a left ventricular ejection fraction (LVEF) of 27 +/- 11% was studied by cine and contrast-enhanced magnetic resonance imaging. RESULTS: Necrotic areas of delayed contrast enhancement were present in every patient and involved 20 +/- 8% of left ventricular myocardium. In involved segments, the transmural extent of contrast enhancement varied from 5% to 100%, being on average 38 +/- 25% of the wall thickness. End-diastolic left ventricular wall thickness and systolic wall thickening were lower in contrast-enhanced segments than in the other segments (P < 0.001). Furthermore, although left ventricular wall thickness and systolic wall thickening decreased as the transmural extent of contrast enhancement increased, the correlations were weak (r = -0.382 and -0.45, respectively). Finally, a delayed contrast enhancement was present in 89% of akinetic and in 94% of dyskinetic segments; however, contrast enhancement was also present in 18% of the segments with normal wall motion and in 56% of hypokinetic segments. CONCLUSIONS: Although mechanical markers of myocardial ischaemia substantially reflect the transmural extent of myocardial infarction, none of them can be considered as a substitute for the direct observation of necrotic tissue and its transmural extent, as provided by contrast-enhanced magnetic resonance imaging.