In Vitro Evaluation of the Influence of Pulsatile Intraventricular Pumping on Ventricular Pressure Patterns

Abstract: The Pulsatile catheter (PUCA) pump consists of a single port membrane pump connected to an indwelling valved catheter. This so–called transarterial blood pump was originally designed to be introduced through a superficial artery into the left ventricular cavity to pump blood from the left ventricle into the ascending aorta. By introducing the catheter directly into the thoracic aorta or the pulmonary artery, the possibility is created of applying large–diameter catheter PUCA pumps as left, right, or biventricular assist devices (LVAD, RVAD, or BIVAD) without damaging any of the structures of the heart. The pump performance of an 8 mm PUCA pump prototype (internal diameter catheter, 8 mm; catheter length, 40 cm; stroke volume, 80 ml) was studied in a mock circulation to investigate the influence of pulsatile intraventricular pumping on ventricular pressure patterns. The pumping mode of the PUCA pump was changed from approximately 1: 1 ([n + l]: n) to 1: 2 ([1/2n + l]: n) and 1: 3 ([1/3n + l]: n) in relation to the frequency of a ventricle–simulating membrane pump. Apart from the pumping mode, timing of the PUCA pump driving system (ejection phase) seems to be crucial in obtaining optimal unloading of the ventricle.     

Radiofrequency Catheter Ablation of Sustained Monomorphic Ventricular Tachycardia in Hypertrophic Cardiomyopathy

Monomorphic VT in HCM. Introduction : Incessant monomorphic ventricular tachycardia (VT) with a right bundle branch block morphology and a northwest axis is a rare arrhythmic complication in a patient with hypertrophic cardiomyopathy and apical left ventricular aneurysm.
Methods and Results : The origin of this VT was localized using the following criteria: the presence of entrainment without fusion, equal internals from the stimulus to the beginning of the QRS complex and from the electrogram to the QRS complex during VT, and the first postpacing interval identical to the tachycardia cycle length. Radiofrequency energy applied to the septoapical part of the apical left ventricular aneurysm terminated the tachycardia within 2 seconds.
Conclusion : Using criteria to guide radiofrequency (RF) ablation of VT in patients with coronary artery disease, an incessant monomorphic VT in a patient with hypertrophic cardiomyopathy was successfully ablated.     

Hemoperfusion during Coronary Angioplasty: First European Experience with a New Hemoperfusion Pump

Abstract: Hemolysis tests with fresh human blood were performed in vitro with a new 5 ml, piston–type hemoperfusion pump, designed to prevent myocardial ischemia during coronary angioplasty. Despite driving pressures greater than 3 atmospheres, shear stress greater than 200 Pa, turbulent pump flow, and the presence of occlusive valves, hemolysis proved to be minimal. This effect is explained by the short amount of time that blood is subjected to mechanical forces that cause hemolysis in the system and by the small volumes of blood involved. During clinical application of the system, angina pectoris, electrocardiographic changes, and systemic blood pressure were used as parameters for myocardial ischemia. There was an effective reduction of ischemia during prolonged (10 min) balloon inflation, demonstrated by the absence of angina, minimal electrocardiographic changes, and normal blood pressure. In addition, the system proved to be safe and effective during high—risk angioplasty.     

Two-Year Results of Treatment with Methionyl Human Growth Hormone in Children with Turner Syndrome

ABSTRACT. Methionyl growth hormone (somatrem) in a daily dosage of 4 IU/m² body surface area was administered to 16 girls with Turner syndrome. Low dose ethinyl estradiol (0.1 μg/kg body weight) was added in girls aged 13 years or more. Mean (SD) height velocity increased from 3.4 (0.9) to 7.2 (1.7) and 5.3 (1.3) cm/year in the first and second year, respectively. Bone age advanced 1.8 years over 2 years and predicted adult height was increased. Apart from the occurrence of anti-GH antibodies there were no side effects. In conclusion, somatrem is an efficacious and safe therapy for short stature in Turner syndrome over a period of 2 years. Longer follow-up is needed before conclusions about its effect on final height can be drawn.