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Rolf Jenni

Publications and source records attributed to Rolf Jenni.

At least 19 recordsLinked to original sources
PubMed2006

Functional growth in tissue-engineered living, vascular grafts: follow-up at 100 weeks in a large animal model.

BACKGROUND: Living autologous vascular grafts with the capacity for regeneration and growth may overcome the limitations of contemporary artificial prostheses. Particularly in congenital cardiovascular surgery, there is an unmet medical need for growing replacement materials. Here we investigate growth capacity of tissue-engineered living pulmonary arteries in a growing lamb model. METHODS AND RESULTS: Vascular grafts fabricated from biodegradable scaffolds (ID 18+/-l mm) were sequentially seeded with vascular cells. The seeded constructs were grown in vitro for 21 days using biomimetic conditions. Thereafter, these tissue-engineered vascular grafts (TEVGs) were surgically implanted as main pulmonary artery replacements in 14 lambs using cardiopulmonary bypass and followed up for < or = 100 weeks. The animals more than doubled their body weight during the 2-year period. The TEVG showed good functional performance demonstrated by regular echocardiography at 20, 50, 80, and 100 weeks and computed tomography-angiography. In particular, there was no evidence of thrombus, calcification, stenosis, suture dehiscence, or aneurysm. There was a significant increase in diameter by 30% and length by 45%. Histology showed tissue formation reminiscent of native artery. Biochemical analysis revealed cellularity and proteoglycans and increased collagen contents in all of the groups, analogous to those of native vessels. The mechanical profiles of the TEVG showed stronger but less elastic tissue properties than native pulmonary arteries. CONCLUSIONS: This study provides evidence of growth in living, functional pulmonary arteries engineered from vascular cells in a full growth animal model.

Absorbable Implants↗
PubMed2006

Continuous wave Doppler signal: a mystery.

Doppler echocardiography is an established noninvasive cardiovascular investigational tool. However, the physical nature of the ultrasound beam may lead to unexpected findings in routine echocardiographic examination, which may lead to misdiagnosis and subsequent wrong clinical decisions.

Aortic Valve Stenosis↗
PubMed2005

Validation of noncompaction criteria in dilated cardiomyopathy, and valvular and hypertensive heart disease.

BACKGROUND: Echocardiographic characteristics typical of isolated left ventricular noncompaction (IVNC) have been well defined. The aim of this study was to validate diagnostic criteria of IVNC in valvular or hypertensive heart disease (HHD) or dilated cardiomyopathy. METHODS: We conducted a retrospective analysis of records and blind review of videotapes of all 19 patients with IVNC seen within 7 years in comparison with randomly selected patients from the same study period with dilated cardiomyopathy (31 patients), HHD (22 patients), and chronic severe valvular heart disease: mitral regurgitation (22 patients); aortic regurgitation (20); and aortic stenosis with bicuspid (22) or tricuspid (22) valves. RESULTS: Clinical characteristics and electrocardiographic findings did not differ between IVNC and other diseases. In IVNC, all patients had noncompacted (NC) segments with a 2-layered structure and wall thickening, and in most patients perfused recesses (95%) or hypokinetic segments (89%) were present. Both hypertrabeculation or presence of a meshwork were specific for IVNC, but the sensitivity for IVNC was only 11% for hypertrabeculation, respectively, 68% for meshwork. In dilated cardiomyopathy, perfused recesses (48%) and a 2-layered structure (26%) were seen but without wall thickening of these segments; all NC criteria including wall thickening were fulfilled in one patient (3%) only. In valvular heart disease or HHD, perfused recesses and a 2-layered myocardium were rare: two patients (5%) with aortic stenosis and one patient with HHD (5%) had NC. Although in IVNC wall thickening was confined to the 2-layered myocardial segments, it was diffuse in other diseases. CONCLUSIONS: Although some NC criteria are occasionally found in other heart disease, the combination of all criteria is very specific. All criteria of NC are rarely met in other disease than IVNC (< or = 5%).

Adult↗
PubMed2005

Texture analysis in digitally-acquired echocardiographic images: the effect of JPEG compression and video storage.

The analysis of texture in video-stored echocardiographic images is an established method to characterize myocardial pathologies. We investigated whether or not texture parameters calculated from video-stored images and those derived from the joint photographic expert group (JPEG) format compressed data are equivalent to those calculated from uncompressed digital images. Texture parameters were calculated using uncompressed digital data, images stored on videotape, and three forms of compressed digital data (baseline JPEG, JPEG 2000 and lossless JPEG 2000). Video storage heavily affected most texture parameters. Although first-order texture parameters derived from JPEG-compressed images were generally equivalent to those derived from the uncompressed data, several second-order parameters differed significantly. We conclude that texture of video-stored images is not comparable to that of digitally-stored images and that JPEG compression changes important second-order texture parameters. This observation should be taken into account when analyzing texture of modern image data (uncompressed or compressed) and comparing the results with earlier studies utilizing video-stored data.

Data Compression↗
PubMed2005

Cost-effectiveness of routine intraoperative transesophageal echocardiography in pediatric cardiac surgery: a 10-year experience.

The beneficial effect of transesophageal echocardiography (TEE) on medical and surgical treatment of children with congenital heart disease has been established. Its cost-effectiveness, however, has not been extensively studied. We analyzed reports of 580 routine TEE examinations performed in our institution between January 1994 and December 2003 in patients younger than 17 yr who required congenital cardiac surgery. After excluding patients who died immediately postoperatively, we identified 33 patients (5.7%) who required a second bypass run on clear-cut indication, i.e., surgical reoperation, and who clearly benefited from TEE findings. An estimate of both fixed and variable costs revealed a savings of 850 to 2655 Swiss francs (CHF) ($690 to $2130 US) per child. This figure undoubtedly underestimates the true cost-effectiveness of routine intraoperative TEE in this setting because we used mostly conservative estimates of the benefits and liberal estimates of the costs. The potential benefits of TEE in hemodynamic monitoring and medical management, in reduction of postoperative morbidity, and in improvement in the quality of life are intangible and were not considered. Although benefits and costs vary according to market conditions, patient populations, surgical practice, and technical expertise with TEE, our analysis demonstrates substantial cost-effectiveness in the use of routine TEE during pediatric cardiac surgery.

Cardiac Surgical Procedures↗
PubMed2005

Novel doppler assessment of intracoronary volumetric flow reserve: validation against PET in patients with or without flow-dependent vasodilation.

UNLABELLED: Volumetric blood flow (Q) determination requires simultaneous assessment of mean blood flow velocity and vessel cross-sectional area. At present, no method provides both values. Intracoronary Doppler-based assessment of coronary flow velocity reserve (CFVR) relies on average peak velocity (APV). Because this does not account for changes in velocity profile or vessel area usually occurring with flow-dependent vasodilation, results can be misleading. The aim of this clinical study was to validate against the current gold standard (measurement of myocardial perfusion reserve [MPR] by PET) a new, Doppler-based method for calculating coronary Q and coronary flow reserve (CFR). METHODS: Doppler-based intracoronary Q was measured with a proprietary guidewire device in a nonstenotic coronary artery at baseline and during adenosine-induced hyperemic flow (140 mug/kg/min intravenously during 7 min). Three gate positions were assessed, of which 2 were lying within the vessel and 1 was intersecting the vessel. The zeroth (M(0)) and the first (M(1)) Doppler moments of the intersecting gate were used to calculate mean blood flow velocity (M(1)/M(0)) and vessel area (M(0)), and M(0) of the 2 proximal gates was used to correct for scattering and attenuation. CFR was calculated as hyperemic/resting flow with Q and compared with APV-derived CFVR and with the corresponding segmental MPR obtained with (15)O-labeled water and PET. RESULTS: Q (CFR, 2.60 +/- 1.07) correlated well with PET (MPR, 2.58 +/- 1.11) (r = 0.832, P < 0.005; Bland-Altman limits, -1.42 to 1.09), whereas CFVR did not (r = 0.09, P = not statistically significant; Bland-Altman limits, -3.36 to 2.24). However, in vessels without dilation, there was no difference between CFR, CFVR, and MPR. CONCLUSION: This procedure for intracoronary Q measurement using the proprietary Doppler guidewire system, which accounts for both changes in flow profile and changes in vessel area, allows invasive, accurate assessment of CFR even in the presence of flow-dependent vasodilation.

Adult↗
PubMed2004

Novel gene locus for autosomal dominant left ventricular noncompaction maps to chromosome 11p15.

BACKGROUND: Left ventricular noncompaction (LVNC) is a congenital unclassified cardiomyopathy with numerous prominent trabeculations and deep intertrabecular recesses in a hypertrophied and hypokinetic myocardium. It has been reported to occur in isolation or in association with congenital heart disease. Mutations in the X-linked G4.5 gene are responsible for cases of isolated LVNC in male infants, but G4.5 mutations were not found in patients with clinical onset of disease in adulthood. In addition, several families with LVNC and an autosomal dominant pattern of inheritance suggest genetic heterogeneity. METHODS AND RESULTS: We performed a genome-wide linkage analysis in a family with autosomal dominant LVNC and show that a locus containing the LVNC disease gene maps to chromosome 11p15. A peak 2-point logarithm of odds score of 5.06 was obtained with marker D11S902 at theta=0. Haplotype analysis defined a critical interval of 6.4 centimorgan between D11S1794 and D11S928 corresponding to a physical distance of 6.8 megabases. No disease-causing mutation was identified in 2 prime positional candidate genes, muscle LIM protein (MLP) and SOX6. CONCLUSIONS: We have mapped a locus for autosomal dominant LVNC to a 6.8-megabase region on human chromosome 11p15. Identification of the disease gene will allow genetic screening and provide fundamental insight into the understanding of myocardial morphogenesis.

Adolescent↗
PubMed2004

Pulmonary arterial hypertension related to HIV infection: improved hemodynamics and survival associated with antiretroviral therapy.

This study aimed to assess the long-term course of pulmonary arterial hypertension related to infection with human immunodeficiency virus (PAHRH) and the influence of antiretroviral therapy (ART) on its characteristics. We retrospectively analyzed all 47 patients in the Swiss HIV Cohort Study in whom PAHRH was diagnosed. Among 35 patients who underwent follow-up Doppler echocardiography, the right ventricular systolic pressure over right atrial pressure gradient increased by a median of 25 mm Hg in 9 patients who had not received ART, decreased by a median of 3 mm Hg in 12 patients who had received nucleoside analogs, and decreased by a median of 21 mm Hg in 14 patients who had received highly active ART (HAART) (P<.005). Among all 47 patients, median duration of survival after PAHRH diagnosis was 2.7 years. HAART significantly decreased mortality due to PAHRH as well as other causes. This study suggests a beneficial effect of combination ART in patients with PAHRH.

Adult↗
PubMed2004

Double aortic and pulmonary valves: An artifact generated by ultrasound refraction.

Echocardiography is an essential diagnostic tool for the investigation of the cardiovascular system. However, the nature of the ultrasound beam may lead to artifacts such as doubling of cardiac structures because of refraction. Here we present two illustrative cases showing doubling of the aortic ring and double regurgitation through the pulmonary valve. Doubling by refraction is different from other artifacts generating double images, such as mirroring of the ultrasound beam (eg, by prosthetic valves). Anatomic structures between the transducer and the heart such as the pleura, pericardium, or rib cartilage may induce refraction of the ultrasound beam resulting in doubling of cardiac structures. The resulting doubling of anatomic structures must not be misdiagnosed.

Aortic Valve↗
PubMed2004

Regional myocardial ischemia in hypertrophic cardiomyopathy: impact of myectomy.

OBJECTIVE: Chest pain is a common finding in patients with hypertrophic cardiomyopathy and can be observed in 40% to 50% of all patients. However, the pathogenesis of these ischemia-like symptoms is still unclear. METHODS: Twenty-two patients with hypertrophic cardiomyopathy and 15 controls underwent positron emission tomography for evaluation of regional myocardial perfusion and coronary flow reserve (hyperemic/baseline myocardial blood flow). Myocardial perfusion (mL/min/g) was measured using [(13)N]ammonia at rest and during hyperemia with dipyridamole (0.56 mg/kg intravenously). Regional coronary flow reserve was assessed in 3 planes (apical, midventricular, basal) in 4 regions (septal, anterior, lateral, inferior). Patients were divided into 2 groups: group 1 consisted of 11 patients treated with surgical myectomy (age 56 +/- 10 years) and group 2 consisted of 11 patients treated medically (age 53 +/- 13 years). RESULTS: Mean global coronary flow reserve was 3.87 +/- 0.92 in controls but 2.31 +/- 0.40 in operated (P <.001 vs controls) and 1.76 +/- 0.58 in medically treated patients (P <.001 vs controls, P <.05 vs operated). Similarly, septal coronary flow reserve was 4.19 +/- 1.22 in controls but significantly reduced in operated patients (2.26 +/- 0.48, P <.001 vs controls) and in medically treated patients (1.76 +/- 0.58; P <.001 vs controls). However, septal flow reserve was significantly higher in operated patients than in patients with medically treated hypertrophic cardiomyopathy (+37%, P <.05), mainly due to a reduced resting myocardial perfusion. CONCLUSIONS: Global and regional myocardial perfusion is reduced in patients with hypertrophic cardiomyopathy. However, myectomy may have a beneficial effect on septal perfusion and flow reserve. Thus, ischemia seems to play an important role in the symptomatology and pathophysiology of hypertrophic cardiomyopathy.

Cardiomyopathy, Hypertrophic↗
PubMed2004

A novel in vivo procedure for volumetric flow measurements.

We report on a novel procedure for invasive volumetric blood flow measurements using a commercially available Doppler flow wire system, which could, until now, only measure flow velocity. We here describe a method applicable in vivo to generate both velocity and cross-sectional area information from the same pulsed-wave Doppler signal for volumetric flow assessment. We demonstrate its feasibility and validation in vivo in pig coronary arteries. Our Doppler-derived volumetric flow measurements were compared with the respective transit-time flow and showed an excellent correlation (r = 0.969; p < 0.0001). Agreement between transit-time and Doppler-derived flow measurements could be observed for flow conditions ranging from 30 to 180 mL/min. The mean values for the two methods were 71.4 +/- 43.7 mL/min and 71.3 +/- 42.2 mL/min, respectively. We conclude that this technique might possibly be introduced into future clinical practice as an invasive procedure of choice for the assessment of volumetric blood flow.

Animals↗
PubMed2004

Gated (99m)Tc-tetrofosmin SPECT for discriminating infarct from artifact in fixed myocardial perfusion defects.

UNLABELLED: Soft-tissue attenuation artifacts generally appear as fixed perfusion-scan defects. Gated (99m)Tc-tetrofosmin SPECT may help differentiate myocardial infarction (MI) from artifacts, as fixed defects with decreased function (wall motion and thickening) probably represent MI, whereas attenuation artifacts represent preserved function. METHODS: Ungated stress and gated rest (99m)Tc-tetrofosmin SPECT was performed on 153 consecutive patients referred for evaluation of coronary artery disease. From stress and summed gated rest images, 107 patients (70%) were identified with isolated fixed defects. The function of the defects was assessed semiquantitatively from gated stress images. The findings were correlated with clinical (history or electrocardiographic Q waves) evidence of MI. RESULTS: Of 62 patients with fixed defects and clinical MI, 60 (97%) had an abnormal defect function. Of 45 patients with no clinical MI, 16 (36%) had decreased function of the defect, possibly indicating silent MI. In 29 of the 45 patients (64%) with no clinical MI, defect function was normal. Because most (90%) fixed defects with normal systolic function occurred in men with inferior fixed defects (87%) or women with anterior fixed defects (3%), these were most likely attenuation artifacts. By reclassifying the condition of patients with fixed defects and normal function as normal, patients with unexplained fixed defects (no clinical MI) decreased from 29% to 10%. CONCLUSION: Gating adds considerable value to (99m)Tc-tetrofosmin SPECT myocardial perfusion imaging in characterizing fixed defects and potentially improves test specificity.

Adenosine↗