Fulminant liver failure: an indicator of silent myocardial rupture

A 56 year old man presented with an atypical chest infection. Remote inferoposterior myocardial infarction was noted on electrocardiography and transthoracic echocardiography. Hepatic failure developed with sudden gross elevation of liver aminotransferases and coagulopathy. No primary hepatic cause could be identified. Subsequent right heart failure led to transoesophageal echocardiography that revealed a large inoperable ventricular septal defect. Histopathological data showed ischaemic hepatitis and reinfarction of the inferoposterior myocardial wall. Acute cardiac events may be silent and precipitate misleading severe hepatic dysfunction.

Efficacy of transmyocardial laser revascularization and thoracic sympathectomy for the treatment of refractory angina

BACKGROUND

Transmyocardial laser revascularization (TMR) is an effective treatment for relief of refractory angina. This benefit may be mediated by increase in myocardial perfusion or by cardiac denervation. We investigate the efficacy of TMR and thoracic sympathectomy (TS) for relief of angina and whether any clinical benefit is associated with enhanced myocardial perfusion.

METHODS

Twenty consecutive patients with nonrevascularizable coronary arteries and intractable angina were prospectively randomized to have TMR by holmium: yttrium aluminum garnet laser or TS. Subjects were clinically evaluated before, and for 42 months after, surgery. They underwent exercise tolerance testing and rest and stress quantitative perfusion magnetic resonance imaging (MRI) before, and 6 months after surgery.

RESULTS

The demographics of the two groups were similar. There was no perioperative mortality; however, two patients died in the TS group during follow-up. The Canadian Cardiovascular Society angina score improved from 3.4 +/- 0.5 to 2.6 +/- 1.1 (p = 0.06) in the TS group at 6 months but returned to 3.2 +/- 0.7 at 42 months, while in the TMR group it improved from 3.6 +/- 0.5 to 1.9 +/- 0.7 (p = 0.008) at 6 months and deteriorated to 2.5 +/- 0.9 (p = 0.01) after 42 months of surgery. The TMR-treated patients showed significant improvements in the SF-36 scores and Seattle Angina Questionnaire only at 6 months, whereas TS-treated patients did not show amelioration at any time during follow-up. The MRI protocol was completed in 15 of 20 (TMR = 8; TS = 7) patients and no significant differences in qualitative or quantitative perfusion variables were demonstrated in either group.

CONCLUSIONS

A greater clinical benefit was obtained with TMR than with TS early after surgery but this clinical effect did not seem to be associated with improvement in myocardial perfusion as assessed by MRI and part of the beneficial effect was lost by 42 months after surgery.

Does the type of prosthesis influence early left ventricular mass regression after aortic valve replacement? Assessment with magnetic resonance imaging

BACKGROUND

Debate exists regarding selection of the prosthesis type most likely to maximize early left ventricular (LV) mass regression after aortic valve replacement (AVR) for stenotic valvular disease. The aim of this study was to compare the degree of LV mass regression measured by MRI 6 months after prospectively randomized valve implantation for two biological prostheses, stented and stentless, and for two mechanical valves, tilting disc and bileaflet.

METHODS

Thirty-nine consecutive patients with predominant aortic stenosis accepted for elective AVR were studied. Twenty patients requiring a tissue prosthesis were randomly assigned to receive either a Freestyle or Mosaic valve. The remaining 19 patients in whom mechanical prosthesis was indicated were randomly assigned to receive either an Ultracor or an ATS valve.

RESULTS

There was no difference in valve size implanted between the compared groups. LV mass measurements were performed with MRI (1.5-T Vision, Siemens, Germany) immediately before and 6 months after surgery. All valve types produced significant postoperative reduction in LV mass compared with preoperative values (P <.01). Percent change in LV mass regression was similar between the two porcine valve types, Mosaic (24.4% +/- 11.1%) and Freestyle (21.1% +/- 16.7%), and between the two mechanical valve designs, Ultracor (19.3% +/- 9.5%) and ATS (26.3% +/- 10.8%), respectively.

CONCLUSIONS

Significant LV remodeling occurs early after AVR for aortic stenosis. The degree of regression in LV mass is independent of prosthesis type implanted.

Magnetic resonance perfusion imaging in patients with coronary artery disease: a qualitative approach

Although contrast-enhanced first pass magnetic resonance imaging (MRI) has potential to quantify blood flow through extensive image post-processing, clinical utility is likely to depend on rapid qualitative analysis.

AIMS

To investigate use of an on-line analytical approach for detection of coronary artery disease (CAD).

METHODS AND RESULTS

Thirty subjects with CAD underwent contrast-enhanced rest/adenosine stress MRI with basal, mid-papillary and apical short-axis image acquisition. Each short axis was divided into eight regions of interest (ROI). Regional perfusion was visually classified as normal or impaired according to transmural distribution and defect reversibility. MRI and angiographic data were compared. Qualitative MRI reporting was possible for 98% ROI. Eighty-six coronary artery (CA) territories were assessed of which 71 (83%) had stenoses. Sensitivity and specificity for detection of stenoses were 93 and 60%, respectively. The proportion of hypoperfused ROI rose from 31% with < 50% stenosis to 65% with occlusion. More transmural defects were seen in infarction-related territories (75 vs. 54%, p < 0.05). More ROI demonstrated defect reversibility in occluded rather than in stenosed infarction-related vessels (89 vs. 58%, p < 0.05). Occluded vessels with grade 2-3 collaterals contained a higher proportion of normal ROI (44 vs. 25%, p < 0.05).

CONCLUSIONS

Qualitative MRI analysis had high sensitivity and moderate specificity for detecting CA stenoses. Additional information was obtained relating to lesion severity, previous infarction, myocardial viability and impact of collateral circulation. The technique has potential for de novo diagnosis of CAD and as a complementary modality to angiography to assess the significance of given angiographic lesions.

Restoration of myocardial blood flow following percutaneous coronary balloon dilatation and stent implantation: assessment with qualitative and quantitative contrast-enhanced magnetic resonance imaging

AIM

To examine the serial use of magnetic resonance imaging (MRI) to evaluate regional myocardial perfusion changes following percutaneous coronary angioplasty and stent implantation (PTCA).

MATERIALS AND METHODS

Six patients with single vessel coronary artery disease (CAD) underwent contrast-enhanced first pass MRI immediately prior to (visit A) and within 7 days after (visit B) PTCA. Three sequential short axis slices were obtained after gadodiamide (Gd) bolus (0.025 mmol/kg(-1)) at rest and during adenosine. Each short axis was divided radially into eight regions of interest (ROIs). ROIs were anatomically assigned to a coronary artery territory (CAT). Stress and rest qualitative and quantitative (unidirectional extraction fraction constant (K(i)); index of myocardial perfusion reserve (MPRI) = stressK(i) / restK(i)) perfusion parameters were determined for ROI supplied by remote and stenosed/stented vessels for each visit.

RESULTS

In stented ROIs the number of ROIs demonstrating normal perfusion, as opposed to reversible perfusion deficits, increased. Qualitative perfusion assessment in remote CATs was unchanged. MPRI in stenotic CATs was lower than in remote CATs at visit A (P < 0.001). Following PTCA, MPRI increased in stented CATs (P < 0.001) but was unchanged in remote CATs.

CONCLUSION

Restoration of myocardial perfusion following PTCA can be delineated with qualitative and quantitative perfusion MRI. Although at present the investigation is technically complex and not perfectly sensitive or specific, MRI has the potential to be a valuable tool for patient follow-up and evaluation of revascularization strategy efficacy.

Interpreting regional myocardial magnetic resonance imaging data: a new method for collation with angiographic findings in patients with coronary artery disease

The magnetic resonance imaging (MRI) assessment of myocardial function and perfusion is a valuable complementary technique to coronary angiography. We describe a method of presenting and collating regional MRI data with the angiographic findings as annotated by the Green Lane reporting system. Routine clinical use of this approach is likely to increase the accuracy of MRI data interpretation and to influence both medical and interventional treatment strategies.

Coronary artery disease: combined stress MR imaging protocol-one-stop evaluation of myocardial perfusion and function

The authors developed and tested a dual stress magnetic resonance (MR) imaging protocol to evaluate myocardial perfusion, function, and hibernation. The technique was well tolerated, and high-quality images were achieved. The comprehensive information obtained can be used to guide clinical management decisions regarding coronary artery revascularization procedures. This protocol offers a one-stop assessment of patients with coronary artery disease with use of a clinical MR imager.

High-dose intravenous glucagon in severe tricyclic poisoning

A case of dothiepin poisoning complicated by cardiogenic shock is described. Hypotension was resistant to conventional inotropes but responded rapidly to high-dose intravenous glucagon. Glucagon should be considered as a useful therapeutic positive inotrope and a potentially antiarrhythmic agent in severe tricyclic antidepressant overdose.