Visualization of transcoronary ablation of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: a comparison between cardiac MRI, invasive measurements and echocardiography.

OBJECTIVE: Hypertrophic obstructive cardiomyopathy (HOCM) is treated by surgical myectomy or transcoronary ablation of septal hypertrophy (TASH). The aim of this study was to visualize the feasibility, success and short-term results of TASH on the basis of cardiac MRI (CMR) in comparison with cardiac catheterization and echocardiography. METHODS: In this in vivo study, nine patients with HOCM were treated with TASH. Patients were evaluated by transthoracic echocardiography, invasive cardiac angiography and CMR. Follow-up examinations were carried out after 1, 3 and 12 months. MR imaging was performed on a 1.5-T scanner. All images were processed using the semiautomatic Argus software and were evaluated by an attending thoracic radiologist and cardiologist. RESULTS: The echocardiographic pressure gradient (at rest) was 69.3 +/- 15.3 mmHg before and 22.1 +/- 5.7 mmHg after TASH (P < 0.01, n = 9). The flux acceleration over the aortic valve examined (V (max)) was 5.1 +/- 0.6 m/s before and 3.4 +/- 0.3 m/s after the TASH procedure (P < 0.05). Also, there was a decrease of septum thickness from 22.0 +/- 1.2 to 20.2 +/- 1.0 mm (P < 0.05) after 6 +/- 3 weeks. The invasively assessed pressure gradient at rest was reduced from 63.7 +/- 15.2 to 21.2 +/- 11.1 mmHg (P < 0.01) and the post-extrasystolic gradient was reduced from 138.9 +/- 12.7 to 45.6 +/- 16.5 mmHg (P < 0.01). All differences as well as the quantity of injected ethanol were plotted against the size or amount of scar tissue as assessed in the MRI. There was a statistically significant correlation between the post-extrasystolic gradient decrease and the amount of scar tissue (P = 0.03, r (2) = 0.5). In addition, the correlation between the quantity of ethanol and scar tissue area was highly significant (P < 0.01, r (2) = 0.6), whereas the values for the gradient deviation (P = 0.10, r (2) = 0.34), DeltaV (max) (P = 0.12, r (2) = 0.31), as well as the gradient at rest (P = 0.27, r (2) = 0.17) were not significant. CONCLUSION: TASH was consistently effective in reducing the gradient in all patients with HOCM. In contrast to the variables investigated by echocardiography, the invasively measured post-extrasystolic gradient correlated much better with the amount of scar tissue as assessed by CMR. We conclude that the optimal modality to visualize the TASH effect seems to be a combination of CMR and the invasive identification of the post-extrasystolic gradient.

[Extramedullary hematopoiesis in the paravertebral space]. / Extramedulläre Blutbildung im paravertebralen Raum.

BACKGROUND: Extramedullary hematopoiesis is a response of the organism to a deficient production of blood-forming cells within the bone marrow. It may coincide with some hematologic diseases. Two patients with paravertebral mass lesions representing extramedullary hematopoiesis are discussed. Characteristic findings of extramedullary hematopoiesis are presented along with a review of the literature on this topic. CASE REPORTS: A 76-year-old male with a known myelodysplastic syndrome presented with pneumonia. In addition, he had symptoms of a cauda equina syndrome with complaints of pain and hypesthesia of the lower limbs as well as urinary retention. A 63-year-old female presented with aggravated complaints of the lower thorax, low back pain radiating to the upper left leg, and dysesthesia of both feet. In her past medical history, she had polycythemia vera and a splenectomy. Both patients showed paravertebral and intraspinal lesions located in the thoracic and sacral spine which were regarded as extramedullary hematopoiesis according to the imaging findings in MRI and CT. Radiation therapy showed marked improvement in their neurologic complaints following the initial sessions. CONCLUSION: Clinical presentation, knowledge of the underlying disease and of imaging findings are essential in the diagnosis of extramedullary hematopoiesis. MRI is the imaging modality of choice in the primary diagnosis of extramedullary hematopoiesis. Possible extension of the disease into the intraspinal space can be evaluated with high accuracy and differential diagnosis can be facilitated. In addition, MRI is of use in the accurate planning of radiation fields as well as during follow-up of extramedullary hematopoiesis.