Peter G. Danias

American College of Cardiology/European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy: a report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines

A 29-year-old Dominican man with a history of intravenous heroin use and hepatitis C presented with a 5-day history of fever, dyspnoea, haemoptysis, pleuritic chest pain, abdominal pain, haematochezia and haematemesis. Initial physical examination was significant for scleral icterus, generalised abdominal tenderness to palpation, melaena and blood-tinged sputum. Blood cultures grew Fusobacterium species. CT scan of the chest revealed multiple bilateral cavitary features in lung fields. At the same time, a neck ultrasound performed demonstrated thrombophlebitis in the right internal jugular vein, confirming the diagnosis of ‘Lemierre’s syndrome’. Treatment was with antibiotics and supportive care for 6 weeks.

Improved Coronary Artery Definition With T2-Weighted, Free-Breathing, Three-Dimensional Coronary MRA

BACKGROUND Three-dimensional (3D) navigator-gated and prospectively corrected free-breathing coronary magnetic resonance angiography (MRA) allows for submillimeter image resolution but suffers from poor contrast between coronary blood and myocardium. Data collected over >100 ms/heart beat are also susceptible to bulk cardiac and respiratory motion. To address these problems, we examined the effect of a T2 preparation prepulse (T2prep) for myocardial suppression and a shortened acquisition window on coronary definition. METHODS AND RESULTS Eight healthy adult subjects and 5 patients with confirmed coronary artery disease (CAD) underwent free-breathing 3D MRA with and without T2prep and with 120- and 60-ms data-acquisition windows. The T2prep resulted in a 123% (P<0. 001) increase in contrast-to-noise ratio (CNR). Coronary edge definition was improved by 33% (P<0.001). Acquisition window shortening from 120 to 60 ms resulted in better vessel definition (11%; P<0.001). Among patients with CAD, there was a good correspondence with disease. CONCLUSIONS Free-breathing, T2prep, 3D coronary MRA with a shorter acquisition window resulted in improved CNR and better coronary artery definition, allowing the assessment of coronary disease. This approach offers the potential for free-breathing, noninvasive assessment of the major coronary arteries.

American College of Cardiology/ European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy A Report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines

This document has been developed as a Clinical Expert Consensus Document (CECD), combining the resources of the American College of Cardiology Foundation (ACCF) and the European Society of Cardiology (ESC). It is intended to provide a perspective on the current state of management of patients with hypertrophic cardiomyopathy. Clinical Expert Consensus Documents are intended to inform practitioners, payers, and other interested parties of the opinion of the ACCF and the ESC concerning evolving areas of clinical practice and/or technologies that are widely available or new to the practice community. Topics chosen for coverage by expert consensus documents are so designed because the evidence base, the experience with technology, and/or the clinical practice are not considered sufficiently well developed to be evaluated by the formal American College of Cardiology/American Heart Association (ACC/AHA) Practice Guidelines process. Often the topic is the subject of considerable ongoing investigation. Thus, the reader should view the CECD as the best attempt of the ACC and the ESC to inform and guide clinical practice in areas where rigorous evidence may not yet be available or the evidence to date is not widely accepted. When feasible, CECDs include indications or contraindications. Some topics covered by CECDs will be addressed subsequently by the ACC/AHA Practice Guidelines Committee. The Task Force on Clinical …

Double-oblique free-breathing high resolution three-dimensional coronary magnetic resonance angiography

OBJECTIVES The goal of the present study was to develop a strategy for three-dimensional (3D) volume acquisition along the major axes of the coronary arteries. BACKGROUND For high-resolution 3D free-breathing coronary magnetic resonance angiography (MRA), coverage of the coronary artery tree may be limited due to excessive measurement times associated with large volume acquisitions. Planning the 3D volume along the major axis of the coronary vessels may help to overcome such limitations. METHODS Fifteen healthy adult volunteers and seven patients with X-ray angiographically confirmed coronary artery disease underwent free-breathing navigator-gated and corrected 3D coronary MRA. For an accurate volume targeting of the high resolution scans, a three-point planscan software tool was applied. RESULTS The average length of contiguously visualized left main and left anterior descending coronary artery was 81.8 +/- 13.9 mm in the healthy volunteers and 76.2 +/- 16.5 mm in the patients (p = NS). For the right coronary artery, a total length of 111.7 +/- 27.7 mm was found in the healthy volunteers and 79.3 +/- 4.6 mm in the patients (p = NS). Comparing coronary MRA and X-ray angiography, a good agreement of anatomy and pathology was found in the patients. CONCLUSIONS Double-oblique submillimeter free-breathing coronary MRA allows depiction of extensive parts of the native coronary arteries. The results obtained in patients suggest that the method has the potential to be applied in broader prospective multicenter studies where coronary MRA is compared with X-ray angiography.

Contrast agent‐enhanced, free‐breathing, three‐dimensional coronary magnetic resonance angiography

For free‐breathing, high‐resolution, three‐dimensional coronary magnetic resonance angiography (MRA), the use of intravascular contrast agents may be helpful for contrast enhancement between coronary blood and myocardium. In six patients, 0.1 mmol/kg of the intravascular contrast agent MS‐325/AngioMARK™ was given intravenously followed by double‐oblique, free‐breathing, three‐dimensional inversion‐recovery coronary MRA with real‐time navigator gating and motion correction. Contrast‐enhanced, three‐dimensional coronary MRA images were compared with images obtained with a T2 prepulse (T2Prep) without exogenous contrast. The contrast‐enhanced images demonstrated a 69% improvement in the contrast‐to‐noise ratio (6.6 ± 1.1 vs. 11.1 ± 2.5; P < 0.01) compared with the T2Prep approach. By using the intravascular agent, extensive portions (> 80 mm) of the native left and right coronary system could be displayed consistently with sub‐millimeter in‐plane resolution. The intravascular contrast agent, MS‐325/AngioMARK™, leads to a considerable enhancement of the blood/muscle contrast for coronary MRA compared with T2Prep techniques. The clinical value of the agent remains to be defined in a larger patient series. J. Magn. Reson. Imaging 1999;10:790–799.

Likelihood of Spontaneous Conversion of Atrial Fibrillation to Sinus Rhythm

OBJECTIVES We sought to determine the likelihood and predictors of spontaneous conversion to sinus rhythm of recent-onset atrial fibrillation (symptoms <72 h). BACKGROUND Although spontaneous conversion of recent-onset atrial fibrillation is common, the likelihood and clinical and echocardiographic predictors have not been fully defined. Such data would be important for management of patients in whom early cardioversion is desired: Cardioversion could be delayed in patients with a high likelihood of spontaneous conversion, and it could be expeditiously pursued if spontaneous conversion is unlikely. METHODS We screened 1,822 consecutive adults admitted to the hospital with atrial fibrillation and prospectively identified 356 patients (45% male, mean age +/- SD 68 +/- 16 years) with atrial fibrillation of <72-h duration. The occurrence of spontaneous conversion to sinus rhythm and clinical and echocardiographic data were identified through retrospective chart review. RESULTS Spontaneous conversion to sinus rhythm occurred in 68% of the study group (n = 242; 95% confidence interval [CI] 63% to 73%). Among patients with spontaneous conversion, the total duration of atrial fibrillation was <24 h in 159 (66%), 24 to 48 h in 42 (17%) and >48 h in 41 (17%) (p < 0.001). Logistic regression analysis of clinical data identified presentation <24 h from onset of symptoms as the only predictor of spontaneous conversion (odds ratio 1.8, 95% CI 1.4 to 2.4, p < 0.0001). Normal left ventricular systolic function was more common among patients with spontaneous conversion (p = 0.03), but it was not an independent predictor of conversion. Left atrial dimension was similar between groups. CONCLUSIONS Spontaneous conversion to sinus rhythm occurs in almost 70% of patients presenting with atrial fibrillation of <72-h duration. Presentation with symptoms of <24-h duration is the best predictor of spontaneous conversion.

Electrocardiogram-gated single-photonemission computed tomography versus cardiacmagnetic resonance imaging for the assessmentof left ventricular volumes and ejection fraction: A meta-analysis

OBJECTIVES The purpose of this study was to evaluate the accuracy of electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) for assessment of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) compared with the gold standard of cardiac magnetic resonance imaging (MRI). BACKGROUND Several comparisons of ECG-gated SPECT with cardiac MRI have been performed for evaluation of LV volumes and EF, but each has considered few subjects, thus leaving uncertainty about the frequency of discrepancies between the two methods. METHODS We performed a meta-analysis of data on 164 subjects from nine studies comparing ECG-gated SPECT versus cardiac MRI. Data were pooled in correlation and regression analyses relating ECG-gated SPECT and cardiac MRI measurements. The frequency of discrepancies of at least 30 ml in EDV, 20 ml in ESV and 5% or 10% in EF and concordance for EF < or =40% versus >40% were determined. RESULTS There was an overall excellent correlation between ECG-gated SPECT and cardiac MRI for EDV (r = 0.89), ESV (r = 0.92) and EF (r = 0.87). However, rates of discrepancies for individual subjects were considerable (37% [95% confidence interval [CI], 26% to 50%] for at least 30 ml in EDV; 35% [95% CI, 23% to 49%] for at least 20 ml in ESV; 52% [95% CI, 37% to 63%] for at least 5% in EF; and 23% [95% CI, 11% to 42%] for at least 10% in EF). The misclassification rate for the 40% EF cutoff was 11%. CONCLUSIONS Electrocardiogram-gated SPECT measurements of EDV, ESV and EF show high correlation with cardiac MRI measurements, but substantial errors may occur in individual patients. Electrocardiogram-gated SPECT offers useful functional information, but cardiac MRI should be used when accurate measurement is required.

Single breath-hold slice-following CSPAMM myocardial tagging

Myocardial tagging has shown to be a useful magnetic resonance modality for the assessment and quantification of local myocardial function. Many myocardial tagging techniques suffer from a rapid fading of the tags, restricting their application mainly to systolic phases of the cardiac cycle. However, left ventricular diastolic dysfunction has been increasingly appreciated as a major cause of heart failure. Subtraction based slice-following CSPAMM myocardial tagging has shown to overcome limitations such as fading of the tags. Remaining impediments, to this technique, however, are extensive scanning times (∼10 min), the requirement of repeated breath-holds using a coached breathing pattern, and the enhanced sensitivity of artifacts related to poor patient compliance or inconsistent depths of end-expiratory breath-holds. We therefore propose a combination of slice-following CSPAMM myocardial tagging with a segmented EPI imaging sequence. Together with an optimized RF excitation scheme, this enables to acquire as many as 20 systolic and diastolic grid-tagged images per cardiac cycle with a high tagging contrast during a short period of sustained respiration.

Comparison of aortic elasticity determined by cardiovascular magnetic resonance imaging in obese versus lean adults

The vascular properties of large vessels in the obese have not been adequately studied. We used cardiovascular magnetic resonance imaging to quantify the cross-sectional area and elastic properties of the ascending thoracic and abdominal aorta in 21 clinically healthy obese young adult men and 25 men who were age-matched lean controls. Obese subjects had greater maximal cross-sectional area of the ascending thoracic aorta (984 +/- 252 vs 786 +/- 109 mm(2), p <0.01) and of the abdominal aorta (415 +/- 71 vs 374 +/- 51 mm(2), p <0.05). When indexed for height the differences persisted, but when indexed for body surface area, a significant difference between groups was found only for the maximal abdominal aortic cross-sectional area. The obese subjects also had decreased abdominal aortic elasticity, characterized by 24% lower compliance (0.0017 +/- 0.0004 vs 0.0021 +/- 0.0005 mm(2)/kPa/mm, p <0.01), 22% higher stiffness index beta (6.0 +/- 1.5 vs 4.9 +/- 0.7, p <0.005), and 41% greater pressure-strain elastic modulus (72 +/- 25 vs 51 +/- 9, p <0.005). At the ascending thoracic aorta, only the pressure-strain elastic modulus was different between obese and lean subjects (85 +/- 42 vs 65 +/- 26 kPa, respectively; p <0.05), corresponding to a 31% difference-but arterial compliance and stiffness index were not significantly different between groups. In clinically healthy young adult obese men, obesity is associated with increased cross-sectional aortic area and decreased aortic elasticity.

Dynamic exercise normalizes resting blood pressure in mildly hypertensive premenopausal women

BACKGROUND Dynamic exercise acutely and transiently lowers resting blood pressure in hypertensive men and is termed postexercise hypotension (PEH). We examined 18 premenopausal women (7 hypertensive and 11 normotensive) to determine if PEH occurs in women and to elucidate possible hemodynamic and hormonal mechanisms. METHODS AND RESULTS Patients wore an ambulatory blood pressure monitor throughout the day after 40 minutes of a rest sham session and 40 minutes of cycle exercise, of which 30 minutes was performed at 60% of maximal oxygen consumption. Cardiac output and total systemic vascular resistance were determined by Doppler echocardiography before and 15 minutes after sham and exercise. Catecholamines, plasma renin activity, and beta-endorphin were measured over this same period. PEH occurred only in the hypertensive women. Systolic, diastolic, and mean arterial blood pressure decreased in the hypertensive women by a mean of 9.5 +/- 2. 8 mm Hg (P <.01), 6.7 +/- 2.4 mm Hg (P <.05), and 7.7 +/- 2.4 mm Hg (P <.05), respectively, for up to 7 hours after versus before exercise, whereas blood pressure was similar in the normotensive women (P >.05). After exercise, total systemic vascular resistance was lower (P <.01), and cardiac output, catecholamines, and plasma renin activity were greater (P <.01) than before exercise in both groups of women. CONCLUSIONS PEH was observed for up to 7 hours after exercise in mildly hypertensive women and was not explained by the hemodynamic and hormonal adjustments that occurred after exercise. The magnitude and duration of PEH may be sufficient to normalize the blood pressure of certain hypertensive women throughout most of the day.