Ultrasound analysis of the relationship between right internal jugular vein and common carotid artery in the left head-rotation and head-flexion position.

Common carotid artery (CCA) injury is a serious complication of internal jugular vein (IJV) cannulation. To minimize unintentional CCA puncture, the anatomic relationship between the IJV and the CCA and the size of IJV were compared under different head positions. Ultrasound analyses of the IJV and the CCA were performed in 103 consecutive patients. Overlapping angle (OA), real puncture angle (RPA) and diameter of IJV (D IJV) were evaluated with 30° and 60° left rotation and with 30° left flexion. When the head position was changed from 30° left rotation to 60° left rotation, OA increased significantly from 6.5° ± 7.7° to 14.5° ± 7.4° at the cricoid cartilage level (Cricoid-level) and from 14.4° ± 8.4° to 20.6° ± 6.9° at the middle triangle level (Triangle-level), whereas RPA decreased significantly at these levels (from 49.7° ± 11.9° to 43.5° ± 13.1° and from 51.1° ± 14.4° to 44.3° ± 13.9°, respectively; P < 0.01 for both). When the head position was changed from 30° left rotation to 30° left flexion, neither OA nor RPA significantly changed (OA: 6.3° ± 6.1° and 15.0° ± 7.2°, RPA: 48.5° ± 12.4° and 51.8° ± 13.6°, P not significant vs 30° left rotation). There was no difference in D IJV when comparing 30° left rotation and 30° left flexion, although D IJV was largest at 60° left rotation. RPA positively correlated with age, and D IJV positively correlated with body mass index. In conclusion, excessive left rotation should be avoided to minimize the probability of unintentional CCA puncture during IJV cannulation. When 30° left rotation is not feasible, the head-flexion position should be utilized.

Comparison of global and regional abnormalities in 99mTc-sestamibi and cardiac magnetic resonance imaging in dilated cardiomyopathy.

OBJECTIVE: The clinical relevance of perfusion defects and increased washout rate (WOR) in (99m)Tc-sestamibi (Tc MIBI) imaging has not been well characterized in dilated cardiomyopathy (DCM). We analyzed abnormalities in Tc MIBI imaging in relation to those in cardiac magnetic resonance (CMR) imaging. METHODS AND RESULTS: Nineteen DCM patients underwent both Tc MIBI and CMR imaging. The perfusion defects and global and regional MIBI WORs were evaluated with planar and single photon emission computed tomography (SPECT) images. The left ventricular function and the delayed enhancement (DE) were estimated with the cine- and DE-mode CMR. In the DCM patients, the Tc MIBI SPECT showed perfusion defects in 65 segments of 14 patients. The global and regional Tc MIBI WORs were higher than those in 10 normal volunteers (19.4 +/- 9.1% vs. 11.7 +/- 6.8% in global and 13.8 +/- 8.6% vs. 9.6 +/- 8.2% in regional WORs; mean +/- SD, P < .01). The DE-mode CMR demonstrated DE in 103 segments of 14 patients. The severity of perfusion defects was correlated with the extent of DE (r = 0.71, P < .01). The regional Tc MIBI WOR was highest in the segments with perfusion defects or DE, but the Tc MIBI WOR in segments without them was also higher than that in the normal volunteers. There was a weak but significant negative correlation between the regional Tc MIBI WOR and wall thickening (r = -0.23, P < .01). CONCLUSIONS: In DCM, the severity of perfusion defects and the increase in Tc MIBI WOR reflect the spread of myocardial fibrosis and/or scar. The increase in Tc MIBI WOR is potentially associated with regional dysfunction of LV wall.

Delayed enhancement on cardiac magnetic resonance and clinical, morphological, and electrocardiographical features in hypertrophic cardiomyopathy.

BACKGROUND: The clinical, morphological, and electrocardiographical relevance of delayed enhancement (DE) in cardiac magnetic resonance (CMR) was studied in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: A total of 56 patients underwent both gadolinium-enhanced CMR and 12-lead electrocardiogram. The CMR demonstrated DE at the left ventricular (LV) wall in 39 patients. The patients with DE included more cases with dilated phase of HCM, higher New York Heart Association (NYHA) classes and incidence of ventricular tachyarrhythmias (VT), lower LV ejection fraction (LVEF) and mean LV wall thickness (WT), and a larger ratio of maximum to minimum LVWT. The QRS duration was prolonged and the QRS axis deviated toward left with increases in the DE volume (r = 0.58 and r = 0.41, P < .01). Abnormal Q waves were present in 5 patients and the location coincided with the DE segments in 4 patients, but the concordance was not significant. The amplitude of T waves correlated with the ratio of the apex to basal LVWT (r = 0.38, P < .01) and was more negative in cases with DE at the apex. CONCLUSIONS: In HCM, the DE was associated with higher NYHA classes and prevalence of VT, impaired global LV function and asymmetrical hypertrophy, and conduction disturbance, abnormal Q waves, and giant negative T waves.

Usefulness of delayed enhancement magnetic resonance imaging to differentiate dilated phase of hypertrophic cardiomyopathy and dilated cardiomyopathy.

BACKGROUND: The dilated phase of hypertrophic cardiomyopathy (HCM) has a poor prognosis. For correct recognition of such patients, we compared the findings in cardiac delayed enhancement (DE)-magnetic resonance imaging (MRI) between HCM and dilated cardiomyopathy (DCM) patients. METHODS AND RESULTS: Sixty-five patients (HCM 39, DCM 26) underwent gadolinium-DTPA-enhanced MRI. The HCM patients were divided into those with preserved (HCM-P, n = 30) and those with impaired systolic function (HCM-I, n = 9). DE-MRI demonstrated focal or diffuse DE at the left ventricular (LV) wall in 60% of HCM-P and 100% of HCM-I, but in only 12% of DCM. The DE distributed mainly septal to the anterior wall of LV, but the DE volume against whole LV muscle volume was much larger in HCM-I than in HCM-P and DCM (4.1 +/- 6.1% in HCM-P, 14.6 +/- 11.9% in HCM-I, and 0.8 +/- 2.4% in DCM, means +/- SD, P < .05). In HCM, there were weak but significant correlations between DE volume, and LV end-diastolic volume and LV end-systolic volume. In HCM-P, the percent of length shortening in the segments with DE was lower than that without DE. CONCLUSIONS: The HCM patients had more DE than the DCM patients, and DE volume correlated to lower global and local LV function. DE-MRI may be useful to evaluate myocardial damage in HCM patients, and to differentiate the dilated phase of HCM from DCM.

Distribution of late gadolinium enhancement in end-stage hypertrophic cardiomyopathy and dilated cardiomyopathy: differential diagnosis and prediction of cardiac outcome.

BACKGROUND: The prognostic implications of late gadolinium enhancement (LGE) have been evaluated in ischemic and non-ischemic cardiomyopathies. The present study analyzed LGE distribution in patients with end-stage hypertrophic cardiomyopathy (ES-HCM) and with dilated cardiomyopathy (DCM), and tried to identify high risk patients in DCM. METHODS: Eleven patients with ES-HCM and 72 with DCM underwent cine- and LGE-cardiac magnetic resonance and ultrasound cardiography. The patient outcome was analyzed retrospectively for 5years of follow-up. RESULTS: LGE distributed mainly in the inter-ventricular septum, but spread more diffusely into other left ventricular segments in patients with ES-HCM and in a certain part of patients with DCM. Thus, patients with DCM can be divided into three groups according to LGE distribution; no LGE (n=24), localized LGE (localized at septum, n=36), and extensive LGE (spread into other segments, n=12). Reverse remodeling occurred after treatment in patients with no LGE and with localized LGE, but did not in patients with extensive LGE and with ES-HCM. The event-free survival rate for composite outcome (cardiac death, hospitalization for decompensated heart failure or ventricular arrhythmias) was lowest in patients with extensive LGE (92%, 74% and 42% in no LGE, localized LGE, and extensive LGE, p=0.02 vs. no LGE), and was comparable to that in patients with ES-HCM (42%). CONCLUSIONS: In DCM, patients with extensive LGE showed no functional recovery and the lowest event-free survival rate that were comparable to patients with ES-HCM. The analysis of LGE distribution may be valuable to predict reverse remodeling and to identify high-risk patients.

The usefulness of delayed enhancement magnetic resonance imaging for diagnosis and evaluation of cardiac function in patients with cardiac sarcoidosis.

OBJECTIVES: Cardiac involvement is an important prognostic factor in patients with sarcoidosis. We evaluated the usefulness of delayed enhancement MRI (DE-MRI) for diagnosing cardiac sarcoidosis by comparing with nuclear imaging and studying the correlation between DE area and left ventricular (LV) function. METHODS: Twelve patients (male:female 3:9) diagnosed as having sarcoidosis underwent Gd-MRI, myocardial perfusion SPECT (Tl-201, Tc-99m sestamibi), Ga-67 scintigraphy, and/or F-18 FDG-PET. RESULTS: DE was observed in 5 patients, and was positive in 39 (39%) of 100 LV segments. The corresponding perfusion defects in myocardial perfusion SPECT were undetectable in 14 (36%) segments. DE distributed mainly in mid- to epi-myocardium, and the lack of perfusion defects in myocardial perfusion SPECT was more prominent in less transmural DE segments. Two patients with diffuse DE and 1 case with focal DE exhibited positive cardiac uptake in Ga-67 scintigraphy, and 2 other cases with focal DE showed cardiac uptake in F-18 FDG-PET. In 7 patients without DE, there were no significant findings in nuclear imaging. Both LV end-diastolic and end-systolic volume were positively and LV ejection fraction was negatively correlated with the extent of DE area. Four patients treated with corticosteroid showed improvement in nuclear imaging and slight decreases in DE area but no recovery in LV function. CONCLUSIONS: DE-MRI is useful to diagnose the cardiac involvement of sarcoidosis and to evaluate cardiac function. It is likely that the distribution of DE in mid- to epi-myocardium is the characteristic of cardiac sarcoidosis, and the larger DE area may be correlated with poor LV function.

Usefulness of delayed enhancement magnetic resonance imaging for detecting cardiac rupture caused by small myocardial infarction in a case of cardiac tamponade.

Delayed enhancement magnetic resonance imaging (DE-MRI) has excellent spatial resolution and compared with other cardiac imaging techniques it can detect a small myocardial infarction (MI) or a subendocardial infarction. A 76-year-old man was admitted for loss of consciousness because of cardiac tamponade. The cause of tamponade was unknown, but electrocardiography and blood test suggested a recent MI. The removal of 100 ml bloody fluid by immediate pericardiocentesis normalized his hemodynamics, and he regained consciousness. Neither echocardiography nor scintigraphy could determine the location of the MI or rupture, but DE-MRI clearly demonstrated a transmural enhancement in a very narrow range of the lateral wall of the left ventricle. Coronary angiography revealed a severely stenotic lesion in the obtuse marginal branch of the left circumflex artery. DE-MRI is a powerful tool for diagnosing small MI that are undetectable with other imaging. Therefore, DE-MRI should be applied in cases with cardiac tamponade by unknown causes.