Assessment of the coronary venous system in heart failure patients by blood pool agent enhanced whole-heart MRI.

OBJECTIVE: To investigate the feasibility of MRI for non-invasive assessment of the coronary sinus (CS) and the number and course of its major tributaries in heart failure patients. METHODS: Fourteen non-ischaemic heart failure patients scheduled for cardiac resynchronisation therapy (CRT) underwent additional whole-heart coronary venography. MRI was performed 1 day before device implantation. The visibility, location and dimensions of the CS and its major tributaries were assessed and the number of potential implantation sites identified. The MRI results were validated by X-ray venography conventionally acquired during the device implantation procedure. RESULTS: The right atrium (RA), CS and mid-cardiac vein (MCV) could be visualised in all patients. 36% of the identified candidate branches were located posterolaterally, 48% laterally and 16% anterolaterally. The average diameter of the CS was quantified as 9.8 mm, the posterior interventricular vein (PIV) 4.6 mm, posterolateral segments 3.3 mm, lateral 2.9 mm and anterolateral 2.9 mm. Concordance with X-ray in terms of number and location of candidate branches was given in most cases. CONCLUSION: Contrast-enhanced MRI venography appears feasible for non-invasive pre-interventional assessment of the course of the CS and its major tributaries.

Blood oxygen level-dependent magnetic resonance imaging using T2-prepared steady-state free-precession imaging in comparison to contrast-enhanced myocardial perfusion imaging.

BACKGROUND: Diagnosis of inducible myocardial ischemia is important for deciding further diagnosis and therapy in coronary artery disease (CAD). Blood oxygen level-dependent (BOLD) cardiac magnetic resonance imaging (CMR) is a potential method to evaluate myocardial perfusion reserve alternatively to first-pass perfusion using contrast agents. METHODS AND RESULTS: We imaged 46 patients with suspected CAD on a 1.5 T whole-body CMR scanner using a T2-prepared steady-state free-precession (SSFP) BOLD-sensitive sequence and a SSFP-based first-pass sequence. All patients were scanned during rest and after 3 min of adenosine infusion (140 µg/kg/min). For myocardial first-pass visualization 0.1 mmol/kg Gadolinium-based contrast agent was used. In 90 myocardial segments a first-pass perfusion deficit could be seen. Relative BOLD signal increase was significantly lower in patients with perfusion deficits compared to patients without perfusion deficits (p < 0.0001). Patients with non-transmural and with transmural first-pass perfusion deficit also differed significantly for BOLD signal increase (p < 0.0001). ROC analysis showed an area under the curve of 0.83 for the T2-prepared SSFP sequence regarding detection of inducible perfusion deficit. CONCLUSIONS: T2-prepared BOLD imaging allows for visualization of myocardial perfusion reserve in a clinical setting without additional use of contrast agents.

Detection of long-term progression of myocardial fibrosis in Duchenne muscular dystrophy in an affected family: a cardiovascular magnetic resonance study.

BACKGROUND: Detection of myocardial fibrosis and left ventricular dysfunction in Duchenne muscular dystrophy (DMD) is the corner stone for further therapeutic studies. Little is known about the ability of cardiac magnetic resonance imaging (CMR) to evaluate progression of myocardial fibrosis. Aim of our study was to provide CMR data in a previously genotyped DMD family and to evaluate whether progression of myocardial fibrosis could be visualized. METHODS AND RESULTS: DMD genotypes were available in 14 family members. CMR was performed in 4/5 carrier females, in 2/2 affected males and in one healthy family member with normal genotype. Functional images and late gadolinium enhanced (LGE) images in contiguous short-axis orientation were acquired at baseline and follow-up of 1231 days CMR examination could be repeated in three carrier females, in one affected male and in the healthy subject previously scanned. Mean decrease of left ventricular ejection fraction during the follow-up period was 10.5±11.0%, mean progression of LGE volume 11.7±9.5%. CONCLUSIONS: Myocardial fibrosis seems to occur prior to global left ventricular dysfunction in DMD diseased males and carrier females. CMR could be used to evaluate progression of myocardial fibrosis and left ventricular function and may thus serve as an important diagnostic tool in the evaluation of therapeutical options in DMD.

Evaluation of the microcirculation during extracorporeal membrane-oxygenation.

Extracorporeal membrane oxygenation (ECMO) provides pulmonary and circulatory support in critically ill patients (Cardiopulmonary Resuscitation, Acute Respiratory Distress Syndrome, or low output syndrome). Hemodynamic parameters are used for evaluation of the macrocirculation, while the microcirculation is monitored by blood-lactate as a surrogate parameter. We evaluated the microcirculation by orthogonal polarization spectral imaging in a patient during ECMO support. This method was initially proposed to quantify changes of microcirculation in patients with septic shock. However, we were able to non-invasively monitor microcirculatory changes at the bedside during temporary intentional arrest of ECMO due to an exchange of the oxygenator. Using a computerized analyzation model, the flow after ECMO stop in vessels (10-100 microm) in the sublingual mucosa was acutely absent or intermittent, respectively. 120 s after restart, microflow was improved with new ECMO settings compared to baseline, while macrocirculation with a mean arterial pressure of 75 mmHg was present after 60 s. The application of orthogonal polarization spectral imaging might be a valuable technique for evaluation of the microcirculation during extracorporeal circulation. It is rapidly implementable, can be used in vivo, and no invasive probes are required.

Toxic myocarditis due to oral ingestion of hydrofluoric acid.

We report the case of a 32-year-old man, admitted to cardiac care unit with congestive heart failure, caused by a reduced global cardiac function four months after oral hydrofluoric acid ingestion while attempting suicide. Biopsy results of left ventricular myocardium confirmed toxic myocarditis due to ingestion of hydrofluoric acid. This case represents an uncommon example of toxic myocarditis as a long-term complication of oral hydrofluoric acid ingestion. We recommend cardiological follow-up consultations in patients with hydrofluoric acid intoxication for early detection of cardiac deterioration.

Incidence of ventricular tachyarrhythmias during permanent pacemaker therapy in low-risk patients results from the German multicentre EVENTS study.

AIMS: Current studies found an incidence of 12-31% ventricular tachyarrhythmias and sudden cardiac death during cardiac pacing months or even years after pacemaker insertion. MADIT(12) and MUSTT(13) demonstrated that patients with poor LV function after Myocardial infarction (MI) showing non-sustained ventricular tachycardia (nsVT) and inducibility during electrophysiologic testing benefit from an ICD. The present study was dedicated to assess the global incidence of non-sustained ventricular arrhythmias in a general population of pacemaker patients. Special regard was on patients with a potential ICD indication, e.g. those matching the MADIT/MUSTT criteria. METHODS AND RESULTS: Two hundred and thirty-one patients (72 +/- 11 years; 134 men) with an indication for dual chamber pacing entered the study. In all patients pacemaker systems capable of automatic storing of intracardiac electrocardiograms were implanted (Pulsar, Discovery, Guidant). Follow-up time was 15 months after inclusion. In 54 (25.7%) of 210 patients with at least one follow-up, episodes of nsVT were documented by stored electrocardiograms (up to >30 beats, >200 b.p.m.). Multiple-up to nine-episodes of ventricular tachycardia were retrieved in 31 of these patients. Three out of 14 patients with an LVEF <40% after MI presented nsVT during the follow-up. One of these patients received an ICD. CONCLUSION: A significant number of pacemaker patients present with ventricular tachycardia. Intracardiac electrocardiograms and alert functions from pacemakers may enhance physicians' awareness of the patient's intrinsic arrhythmic profile and help uncover underlying mechanisms of arrhythmias by storing the initiation of the arrhythmia.