Evaluation and Management of Cardiac Sarcoidosis with Advanced Imaging.

A high clinical suspicion in the setting of appropriate history, physical exam, laboratory, and imaging parameters is often required to set the groundwork for diagnosis and management. Echocardiography may show septal thinning, evidence of systolic and diastolic dysfunction, along with impaired global longitudinal strain. Cardiac MRI reveals late gadolinium enhancement along with evidence of myocardial edema and inflammation on T2 weighted imaging and parametric mapping. 18F-FDG PET detects the presence of active inflammation and the presence of scar. Involvement of the right ventricle on MRI or PET confers a high risk for adverse cardiac events and mortality.

Scar quantification by cardiovascular magnetic resonance as an independent predictor of long-term survival in patients with ischemic heart failure treated by coronary artery bypass graft surgery.

BACKGROUND: Scar burden by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is associated with functional recovery after coronary artery bypass surgery (CABG). There is limited data on long-term mortality after CABG based on left ventricular (LV) scar burden. METHODS: Patients who underwent LGE CMR between January 2003 and February 2010 within 1 month prior to CABG were included. A standard 16 segment model was used for scar quantification. A score of 1 for no scar, 2 for ≤ 50 % and 3 for > 50 % transmurality was assigned for each segment. LV scar score (LVSS) defined as the sum of segment scores divided by 16. All-cause mortality was ascertained by social security death index. RESULTS: One hundred ninety-six patients met the inclusion criteria. 185 CMR studies were available. History of prior MI was present in 64 % and prior CABG in 5.4 % of patients. Scar was present in 72 % of patients and median LVEF was 38 %. Over a median follow up of 8.3 years, there were 64 deaths (34.6 %). There was no statistically significant difference in mortality between Scar and No-scar groups (37 % versus 29 %). In the group with scar, a lower scar burden (defined either < 4 segments with scar or based on LVSS) was independently associated with increased survival. CONCLUSION: In patients undergoing surgical revascularization, scar burden is negatively associated with survival in patients with scar. However, there is no difference in survival based on presence or absence of scar alone. CMR prior to CABG adds additional prognostic information.

Routine cine-CMR for prosthesis-associated mitral regurgitation: a multicenter comparison to echocardiography.

BACKGROUND AND AIM OF THE STUDY: Mitral regurgitation (MR) is an important complication after prosthetic mitral valve (PMV) implantation. Transthoracic echocardiography is widely used to screen for native MR, but can be limited with PMV. Cine-cardiac magnetic resonance (CMR) holds the potential for the non-invasive assessment of regurgitant severity based on MR-induced inter-voxel dephasing. The study aim was to evaluate routine cine-CMR for the visual assessment of PMV-associated MR. METHODS: Routine cine-CMR was performed at nine sites. A uniform protocol was used to grade MR based on jet size in relation to the left atrium (mild < 1/3, moderate 1/3-2/3, severe > 2/3). MR was graded in each long-axis orientation, with overall severity based on cumulative grade. Cine-CMR was also scored for MR density and pulmonary vein systolic flow reversal (PVSFR). Visual interpretation was compared to quantitative analysis in a single-center (derivation) cohort, and to transesophageal echocardiography (TEE) in a multicenter (validation) cohort. RESULTS: The population comprised 85 PMV patients (59% mechanical valves, 41% bioprostheses). Among the derivation cohort (n = 25), quantitative indices paralleled visual scores, with stepwise increases in jet size and density in relation to visually graded MR severity (both p = 0.001). Patients with severe MR had an almost three-fold increase in quantitative jet area (p = 0.002), and a two-fold increase in density (p = 0.04) than did other patients. Among the multicenter cohort, cine-CMR and TEE (Δ =. 2 ± 3 days) demonstrated moderate agreement (κ = 0.44); 64% of discordances differed by ≤ 1 grade (Δ = 1.2 ± 0.5). Using a TEE reference, cine-CMR yielded excellent diagnostic performance for severe MR (sensitivity, negative predictive value = 100%). Patients with visually graded severe MR also had more frequent PVSFR (p < 0.001), denser jets (p < 0.001), and larger left atria (p = 0.01) on cine-CMR. CONCLUSION: Cine-CMR is useful for the assessment of PMV-associated MR, which manifests concordant quantitative and qualitative changes in size and density of inter-voxel dephasing. Visual MR assessment based on jet size provides an accurate non-invasive means of screening for TEE-evidenced severe MR.

The spectrum of electrocardiographic manifestations of acute myocarditis: an expanded understanding.

BACKGROUND AND PURPOSE: Descriptions of the significance of ST segment or QRS abnormalities in myocarditis are limited because documentation of the diagnosis has previously required myocardial biopsy. Late gadolinium enhancement (LGE) and T2 weighted imaging in the midventricular wall on cardiac magnetic resonance imaging (CMRI) has a very good positive predictive value for the diagnosis of myocarditis. We hypothesized to reexplore the diagnostic value of these electrocardiographic (ECG) changes in myocarditis by utilizing CMRI as the reference standard. METHODS: Data on demographics, clinical presentation, laboratory tests, echocardiograms, coronary angiograms, and computed tomography angiography of 41 consecutive patients with definite midventricular or subepicardial LGE and T2 weighted imaging on CMRI were extracted from the available clinical records. ECGs were blindly examined by two independent readers and divided based on (a) STT changes into: 1. No STT changes, 2. STT changes but no ST elevation, 3. ST elevation (STE); and (b) the presence or absence of QRS abnormalities. Associations of these ECG changes with differences in left ventricular ejection fraction, as measured from CMRI was the main aim of this study. In addition, a complete clinical profile of these patients with myocarditis as identified by CMRI was also created. RESULTS: 80% of our study population were male with a mean age of 38.6±15.5 and a paucity of traditional cardiovascular risk factors (<30%). 90% presented with chest pain with more than half having dyspnea and a viral prodrome, but fever was infrequent (15%). Peak troponin-I and creatine kinase-MB levels exceeded the upper limit of normal in latest 85%, often by more than 5 times the limit. 18% had a coronary luminal narrowing of ≥50%, while 56% had echocardiographic wall motion abnormalities. The left ventricular ejection fraction averaged 54.3±10.8%. In 24.4% of patients, the ECG was entirely normal; while 39% had STE. STT changes did not detect any differences in the ejection fraction. An abnormal QRS, which was present in 29%, was associated with a lower left ventricular ejection fraction (p=0.005). CONCLUSIONS: Patients with clinical features suggestive of myocarditis and confirmatory CMRI findings, can present with a variety of ECG findings, some of which have the potential to identify those with a worse cardiac function, and potentially with a worse prognosis.

The Significance of Parametric Mapping in Advanced Cardiac Imaging.

Cardiac magnetic resonance imaging has witnessed a transformative shift with the integration of parametric mapping techniques, such as T1 and T2 mapping and extracellular volume fraction. These techniques play a crucial role in advancing our understanding of cardiac function and structure, providing unique insights into myocardial tissue properties. Native T1 mapping is particularly valuable, correlating with histopathological fibrosis and serving as a marker for various cardiac pathologies. Extracellular volume fraction, an early indicator of myocardial remodeling, predicts adverse outcomes in heart failure. Elevated T2 relaxation time in cardiac MRI indicates myocardial edema, enabling noninvasive and early detection in conditions like myocarditis. These techniques offer precise insights into myocardial properties, enhancing the accuracy of diagnosis and prognosis across a spectrum of cardiac conditions, including myocardial infarction, autoimmune diseases, myocarditis, and sarcoidosis. Emphasizing the significance of these techniques in myocardial tissue analysis, the review provides a comprehensive overview of their applications and contributions to our understanding of cardiac diseases.

Left ventricular fibroma presenting as syncope and ventricular tachycardia.

Cardiac fibromas represent the second most common benign cardiac mass seen in the pediatric population, but they are rarely seen in adults. Given their large size and unpredictable location within the heart, patients may present with varying symptomatology, and in many cases, the initial presentation is sudden death. Both echocardiography and magnetic resonance imaging are critical to the early diagnosis and prompt treatment of these potentially dangerous primary tumors. We report a 29-year-old woman presenting with syncope and ventricular tachycardia. She was found to have a 5.0 cm inferoapical left ventricular fibroma, which was successfully resected.

Acute myopericarditis due to human granulocytic anaplasmosis.

We present a case of a 54-year-old gentleman with a history of hypertension and chronic HIV who presented with fever and epigastric pain, found to have elevated troponin-I levels and diffuse ST-segement elevations on ECG without clinical evidence of ischemia concerning for myopericarditis. Initial laboratory findings also included thrombocytopenia and elevated aminotransferases as well as computed tomography imaging revealing splenic infarcts. Given plausible exposure to ticks, this led to the eventual diagnosis of anaplasmosis confirmed on PCR assay. Cardiac MRI images confirmed myocardial involvement, which resolved with antibiotic treatment. While rare, cardiac involvement is possible sequelae of anaplasmosis infection as illustrated by this case.

Subclinical brain embolization in left-sided infective endocarditis: results from the evaluation by MRI of the brains of patients with left-sided intracardiac solid masses (EMBOLISM) pilot study.

BACKGROUND: Acute brain embolization (ABE) in left-sided infective endocarditis has significant implications for clinical decision making. The true incidence of ABE, including subclinical brain embolization, is unknown. METHODS AND RESULTS: We prospectively studied 56 patients with definite left-sided infective endocarditis. Patients were examined by a study neurologist, and those without contraindication had magnetic resonance imaging of the brain. Patients without clinical evidence of acute stroke but with magnetic resonance imaging evidence of ABE were considered to have subclinical brain embolization. Clinical stroke was present in 14 of 56 patients (25%). Among 40 patients undergoing magnetic resonance imaging, the incidence rates of subclinical brain embolization and any ABE were 48% and 80%, respectively. ABE was present in 18 of 19 patients (95%) with Staphylococcus aureus infection. At 3 months, mortality was similar among patients with clinical stroke and subclinical brain embolization (62% versus 53%; P=NS) and was higher among patients with any ABE than among those without ABE (56% versus 12%; P=0.046). Valvular surgery was performed in 25 patients (45%), including 16 with ABE, at a median of 4 days. No patient suffered a postoperative neurological complication. Surgery was independently associated with a lower risk of mortality at 3 months (odds ratio, 0.1; 95% confidence interval, 0.03 to 0.6; P=0.008). CONCLUSIONS: Magnetic resonance imaging detected subclinical brain embolization in a substantial number of patients with left-sided infective endocarditis, suggesting that the incidence of ABE may be significantly higher than reports based on clinical and computed tomography findings have indicated. Brain magnetic resonance imaging may play a role in the complex decision about surgical intervention in infective endocarditis.

Arrhythmogenic Right Ventricular Cardiomyopathy Diagnosis.

Arrhythmogenic right ventricular cardiomyopathy, formerly called "arrhythmogenic right ventricular dysplasia," is an under-recognized clinical entity characterized by ventricular arrhythmias and a characteristic ventricular pathology. Diagnosis is often difficult due to the nonspecific nature of the disease and the broad spectrum of phenotypic variations. Therefore, consensus diagnostic criteria have been developed which combine electrocardiographic, echocardiographic, cardiac magnetic resonance imaging and histologic criteria. In 1994, an international task force first proposed the major and minor diagnostic criteria of arrhythmogenic right ventricular cardiomyopathy based on family history, arrhythmias, electrocardiographic abnormalities, tissue characterization, and structural and functional right ventricular abnormalities. In 2010, the task force criteria were revised to include quantitative abnormalities. These diagnostic modalities and the most recent task force criteria are discussed in this review.

Cardiac Magnetic Resonance for Diagnosis and Risk Stratification.

Cardiac MRI (CMR) is an essential tool for the evaluation of the patient with hypertrophic cardiomyopathy (HCM). First, the accurate morphologic imaging and measures that are possible with CMR help to ascertain the diagnosis. Second, the tissue characterization that can be done with MRI helps to define the abnormalities in the myocardium and to identify areas of fibrosis that have been linked to increase risk of sudden cardiac death and heart failure. In addition, CMR can help distinguish HCM from similar disease processes.

Association of size of myocardial scar and persistence of ST-segment elevation after healing of anterior wall myocardial infarction.

Half the patients who survive ST-segment elevation anterior myocardial infarction continue to have ST elevation (STE) 6 months after the event. The mechanism for this and its clinical significance are unclear. There are data to suggest that larger infarcts are more likely to have persistent changes in the ST segment. This study is designed to test this association further using a novel means of assessing the presence and magnitude of myocardial scar using cardiac magnetic resonance imaging (MRI). Delayed imaging by MRI after injection of gadolinium is commonly used to detect myocardial scar through the appearance of delayed contrast hyperenhancement. Consecutive patients referred for myocardial viability imaging were reviewed. The volume of scar as a percentage of anterior wall volume was calculated, and the 26 patients with scar involving >or=10% of the anterior wall were selected for inclusion. All had an electrocardiogram recorded within 15 days of MRI, and none had an intervening cardiac event. Observers unaware of MRI findings independently measured ST-segment changes. Nine patients had STE >1 mm and 17 did not. Mean anterior scar volume in the group without STE was 31.9 +/- 17.1% of the anterior wall volume compared with 50.3 +/- 15.9% in the group with STE >1 mm (p = 0.01). The larger the myocardial scar, the more likely STE was to be present. Only 1 of 10 patients (10%) with scar in the anterior wall <30% had such an elevation compared with 3 of 9 (33%) with scar size of 30% to 49% and 5 of 7 (78%) with scars >or=50%. In conclusion, persistent anterior STE is associated with the size of myocardial scar detected using MRI.

Lack of sensitivity of the electrocardiogram for detection of old myocardial infarction: a cardiac magnetic resonance imaging study.

BACKGROUND: The presence of Q waves in the electrocardiogram (ECG) has been used as a marker of prior myocardial infarction (MI). Its accuracy, however, is uncertain. The purpose of this study is to determine the accuracy of an ECG to detect prior MI compared with a novel criterion standard. METHODS: This study conducted retrospective inclusion with de novo analysis of ECG and cardiac magnetic resonance (CMR) by independent blinded readers in a single-institution setting. The population consisted of a consecutive sample of 146 patients referred for CMR for evaluation of myocardial viability and necrosis. Q/QS waves on ECG were defined as per Minnesota Code criteria. Myocardial scar was quantified and localized by CMR delayed contrast hyperenhancement and assumed as criterion standard. Sensitivity, specificity, and predictive values of ECG were calculated for different scar sizes (>1%, >15%, and >30% of the myocardium) and location (global, anterior, inferior, and lateral walls). RESULTS: Sensitivity was 48.4%; specificity, 83.5; positive predictive accuracy, 72.0%; and negative predictive accuracy, 64.2%. Sensitivity improved when only large infarcts were considered (64.2%), but specificity decreased to 72.7%. Sensitivity for detecting isolated anterior or inferior wall scars was similar, but isolated lateral wall scar was rarely identified (14.3%). When all 3 walls were involved, sensitivity was still low at 57.9%. CONCLUSIONS: The lack of sensitivity and the resulting low negative predictive value of Q/QS criteria seriously limit its accuracy as a marker of prior MI.

Characterization of the coronary sinus ostium by cardiac magnetic resonance imaging.

The diameter and the angle of the coronary sinus (CS) ostium was analyzed in 101 patients who underwent cardiac magnetic resonance imaging and had left ventricular ejection fractions < or =0.35 (n = 40) or > or =0.65 (n = 61). The angle of the CS ostium in patients with LVEFs < or =0.35 was less acute than in patients with LVEFs > or =0.65 (73 degrees +/- 12 degrees vs 65 degrees +/- 10 degrees, p <0.01). There was no statistically significant difference in the diameter of the CS ostium in patients with LVEFs < or =0.35 compared with those with LVEFs > or =0.65 (8 +/- 3 vs 8 +/- 2 mm, p = 0.5). The diameter and the angle of the CS ostium were not different when analyzed on the basis of the duration of the QRS complex, left atrial dimension, or left ventricular end-diastolic dimension. In conclusion, on the basis of cardiac magnetic resonance imaging data, the angle of the CS is less acute in patients with LVEFs < or =0.35 than in those with LVEFs > or =0.65.

New imaging techniques for diagnosing coronary artery disease.

New tomographic cardiovascular imaging tests, such as intravascular ultrasonography (IVUS), coronary computed tomography (CT) angiography and magnetic resonance imaging (MRI), can be used to assess atherosclerotic plaques for the characterization and early staging of coronary artery disease (CAD). Although IVUS images have very high resolution capable of revealing very early preclinical CAD, it is an invasive technique used clinically only in conjunction with a coronary intervention. Multiple-slice coronary CT angiography, which is noninvasive, shows promise as a diagnostic method for CAD. New 64-slice cardiac CT technology has high accuracy for the detection of lesions obstructing more than 50% of the lumen, with sensitivity, specificity, and positive and negative predictive values all better than 90% in patients without known CAD. Cardiac MRI is also improving accuracy in coronary plaque detection and offers a better opportunity for plaque characterization. With further advances in tomographic imaging of coronary atheromas, the goal will be to detect plaques earlier in the development of CAD and to characterize the plaques most likely to generate a clinical event.

Left Ventricular Energy Model Predicts Adverse Events in Women With Suspected Myocardial Ischemia: Results From The NHLBI-Sponsored Women's Ischemia Syndrome Evaluation (WISE) Study.

OBJECTIVES: To assess the prognostic value of a left ventricular energy-model in women with suspected myocardial ischemia. BACKGROUND: The prognostic value of internal energy utilization (IEU) of the left ventricle in women with suspected myocardial ischemia is unknown. METHODS: Women (n=227, mean age 59±12 years, range 31-86), with symptoms of myocardial ischemia, underwent myocardial perfusion imaging (MPI) assessment for regional perfusion defects along with measurement of ventricular volumes separately by gated Single Photon Emission Computed Tomography (SPECT) (n= 207) and magnetic resonance imaging (MRI) (n=203). During follow-up (40±17 months), time to first major adverse cardiovascular event (MACE, death, myocardial infarction or hospitalization for congestive heart failure) was analyzed using MRI and gated SPECT variables. RESULTS: Adverse events occurred in 31 (14%). Multivariable Cox models were formed for each modality: IEU and wall thickness by MRI (Chi-squared 34, p<0.005) and IEU and systolic blood pressure by gated SEPCT (Chi-squared 34, p<0.005). The models remained predictive after adjustment for age, disease history and Framingham risk score. For each Cox model, patients were categorized as high-risk if the model hazard was positive and not high-risk otherwise. Kaplan-Meier analysis of time to MACE was performed for high-risk vs. not high-risk for MR (log rank 25.3, p<0.001) and gated SEPCT (log rank 18.2, p<001) models. CONCLUSIONS: Among women with suspected myocardial ischemia a high internal energy utilization has higher prognostic value than either a low EF or the presence of a myocardial perfusion defect assessed using two independent modalities of MR or gated SPECT.