Evaluation of remote stethoscopy for pediatric telecardiology.

OBJECTIVE: To investigate the interobserver reliability and diagnostic validity of a commercial electronic stethoscope for pediatric telecardiology. MATERIALS AND METHODS: Pairs of blinded pediatric cardiologists made independent diagnoses, recommendations concerning follow-up echocardiography, and specific judgments regarding heart sounds, murmurs, and congenital heart disease using an electronic (ES) or an acoustic (AS) stethoscope on 78 pediatric cardiology outpatients and at a distance of 450 km (280 miles) with 38 telemedicine cardiology outpatients. The kappa statistic (K) indexed the instruments' interexaminer reliabilities. The validity of ES was measured by K for ES versus AS and by the percentage of cases where the findings for ES and AS differed sufficiently to suggest an important ES screening error. RESULTS: For heart disease, AS, ES, and tele-ES reliabilities were satisfactory (K = 0.80, 0.67, and 0.80, respectively), as were AS agreement with hands-on ES (K = 0.65) and with tele-ES (K = 0.64). The AS and ES reliabilities and ES/AS agreement were also satisfactory for systolic regurgitant and diastolic pulmonic murmurs (K = 0.63-0.78) but were unsatisfactory for evaluable heart sounds and other murmurs (K = 0.16-0.60). The ES yielded clinically important disagreements with AS in 5.4% of the clinic cases and 10.5% of the telemedicine cases (P = 0.67). In determining the need for additional work-up (echocardiography) or follow-up appointments, hands-on ES and tele-ES had a combined accuracy of 92%, with a sensitivity of 88% and a specificity of 97%. CONCLUSIONS: Hands-on ES provided reliable and valid screening for congenital heart disease. Tele-ES was highly reliable but had reduced diagnostic validity. Examiner blinding, bandwidth limitations, and artificial restrictions on the remote assistant may have contributed to this reduced performance. As these factors are easily correctable, we regard the ES as a highly promising tool for pediatric telecardiology.

[The influence of modified sequential therapy on lipid metabolism in postmenopausal women]. / Wplyw wlasnej modyfikacji sekwencyjnej estrogenoterapii na przemiany lipidowe u kobiet w okresie pomenopauzalnym.

The study was performed in 50 women aged 49 to 55 years, divided into two groups. Group I received transdermally at a rising dose of 2 to 8 mg, altogether 16 mg during the therapeutic cycle of 20 days. Group II received estriol intravaginally 0.03 mg/day 10 days and 0.06 mg/day for 10 days. During the second part of the therapeutic cycle all women were given progesterone sublingually 25 mg/day for 6 days and 50/day for 6 days. Measurements in serum of total cholesterol, free cholesterol and triglycerides using an enzymic method, of HDL-Ch and LDL-Ch using a precipitation method and of cholesterol esters using thing-layer chromatography were performed before and after 3 months of therapy. It was found that the use of estradiol leads to a significant decrease in the level of triglycerides, total and free cholesterol, LDL-Ch, with a rise in HDL-Ch. The use of estriol leads to a decrease in LDL-Ch only. No changes in the composition of cholesterol esters were found in both groups, with the exception of an insignificant rise in the percentage of cholesterol oleate.

Balloon pulmonary valvuloplasty for isolated pulmonary valvular stenosis.

Fifteen balloon pulmonary valvuloplasties (BPVs) were performed on 13 infants and children with isolated pulmonary valvular stenosis (PVS). There were no complications. Two patients required repeat BPV, one for failure, the other for restenosis. At the time of the 13 latest BPVs, age ranged from three days to 13.1 years (mean 5.7 +/- SD 4.8 years). Average Doppler pulmonary valve pressure gradient preceding BVP was 75 +/- 22 mm Hg. At follow-up it was 25 +/- 9 mm Hg (p < .0001). Follow-up interval was 0.61 to 4.70 years (2.29 +/- 1.18). Restenosis occurred in 1/13 (8%) of the patients. The remaining 12/13 (92%) showed highly satisfactory sustained gradient reductions. Doppler gradients preceding BPV by as much as 4 months correlated highly with catheter gradients at time of BPV, confirming that Doppler echocardiography is a highly accurate indication of PVS severity. Catheterization for PVS should therefore not be used for diagnostic purposes alone. BPV can be performed safely, economically and effectively and is recommended as the treatment of choice for infants and children with moderate to severe isolated PVS. For very young patients, follow-up Doppler surveillance should be done semi-annually; for all others, annually.

Cerebrovascular stenoses with cerebral infarction in a child with Williams syndrome.

We report on a patient with Williams syndrome who suffered a cerebrovascular accident. Clinical evaluation demonstrated the presence of carotid and cerebral arterial stenoses. We believe these lesions led to acute cerebrovascular ischemia and a non-hemorrhagic cerebral infarction. It is possible the stenoses were exacerbated by a vasculitis. The stenoses were identified by both invasive and noninvasive imaging studies. These studies may have a role in the evaluation of persons with Williams syndrome.

Properties of cardiac I(leak) induced by photosensitizer-generated reactive oxygen.

We reported previously that photomodification of single frog cardiac cells by Rose Bengal induces a time-independent current, designated I(leak)++, having a linear current-voltage (I/V) relationship. The purpose of the present study is to better characterize the properties of I(leak)++. Initially, I(leak)++ has a reversal potential (ER) near -70 mV, but with time, ER shifts toward a final value near 0 mV. This shift in ER is accompanied by a marked increase in conductance (slope of I/V relationship). Evidence is presented that the depolarizing shift in ER with time during photomodification results from a loss of membrane selectivity allowing sodium to make an increasing contribution to I(leak)++. Potassium also contributes to I(leak)++, as indicated by marked depolarizing shifts in ER following replacement of intracellular potassium with either cesium or tetraethylammonium. Since these results occur in calcium-free external media, the depolarizing shifts in ER and increased conductance are not related to activation of a calcium-dependent nonselective cation channel. However, I(leak) does have some properties similar to nonselective cation currents recently reported to be activated by membrane breakdown products such as arachidonic acid and lysophosphoglycerides.

[Diagnostic-surgical protocol in female infertility]. / Protokól diagnostyczno-operacyjny nieplodnosci kobiecej.

Diagnostic-operative Protocol of infertility in women, elaborated and being used at the Clinic of Gynaecology--OGI--PMA obliges the operator to evaluate the anatomical status of uterus, ovaries and particularly oviducts in a concise and simultaneously precisely expressed form in points. That also permits for additional, supplementing remarks as well as for providing information on the sketch of internal genital organs. Less emphasis was focussed on the operative procedure description. Relatively much space was left therein for detailed final diagnosis and procedure type definition.

Pediatric cardiology: auscultation from 280 miles away.

New long-distance audio/video and data communications links among health-care facilities promise to reduce rural patients' travel time and waiting time for subspecialty consultations. To offer a satisfactory alternative to face-to-face examination, the long-distance system must meet the subspecialty's minimum criteria. For pediatric cardiology in particular, the system has to permit satisfactory cardiac auscultation. A preliminary test of remote auscultation that uses an electronic stethoscope involved two pediatric cardiologists, one listening hands-on with an acoustic stethoscope, the other listening independently at long distance with the electronic instrument. Taking the acoustic findings as the reference standard, the electronic stethoscope did not miss the one case of heart disease, correctly recommended echocardiogram follow-up in the two cases requiring it, and agreed on 80% of the murmurs' qualitative specifics. The patients' parents also indicated that the system was highly acceptable. We are following up these results with a full-scale study of the effectiveness and parental acceptance of remote auscultation.

[Pharmacologic interaction of lidocaine with aminophylline]. / Interakcja farmakokinetyczna lidokainy z aminofilina.

The interaction between aminophylline and lidocaine after i.v. administration has been described. It appeared that aminophylline lowers liver blood flow what diminishes a lidocaine elimination from organism.

[Effect of propranolol on lidocaine pharmacokinetics]. / Wplyw propranololu na farmakokinetyke lidokainy.

The study aimed at investigating an effect of propranolol on lidocaine pharmacokinetic parameters, especially elimination rate and total clearance rate. The study was carried out in 8 rabbits with cross-over technique. The animals were examined twice. Sequence of therapy was established randomly. Some group of the animals were given propranolol and lidocaine first while the remaining animals were given lidocaine alone. Sequence of drugs administration was changed after one week. Propranolol was given in a single dose of 0.05 mg/kg b.w. intravenously. Lidocaine was injected in a single dose of 3 mg/kg b.w. during 5 minutes i.v. after a 30-minute interval. All drugs were injected into ear vein. Blood for assays was collected 8 times within 6 hours after lidocaine administration. TDx system manufactured by Abbott was used for drug concentration assay with immunofluorescence polarization method. One-compartment open model was used for calculations. The results were analysed with Student t-test for pairs. Significant decrease in AUC, marked decrease in distribution volume and total body clearance following lidocaine and propranolol were noted. The study has shown that there is interaction between propranolol and lidocaine leading to a decrease in total body lidocaine clearance.

Intracellular magnesium affects I(K) in single frog atrial cells.

Voltage-clamp experiments on single frog (Rana pipiens) atrial cells using whole cell recording techniques revealed that the addition of MgCl2 to the 150 mM KCl patch pipette solution influenced the voltage- and time-dependent potassium current (IK). After rupture of the membrane patch under the tip of the pipette, IK increased with time when the pipette solution was magnesium free, but decreased slightly when the solution contained 1.5 mM MgCl2. More dramatic decreases in IK occurred when the solution contained 3.0 or 10 mM MgCl2. In addition to suppressing the magnitude of IK, the activation rate of this current was enhanced by 10 mM MgCl2 but was not affected by 1.5 or 3 mM MgCl2. Other chloride salts containing mono-, di-, or trivalent cations were used to demonstrate that the effects of MgCl2 on IK were not related to alterations in ionic strength, osmolality, or chloride concentration produced by adding MgCl2 to the pipette solution. Our results suggest that changes in the intracellular magnesium concentration influence IK as the pipette solution exchanges with the intracellular fluid.

Neonatal aortic thrombosis complicating umbilical artery catheterization: successful treatment with retroperitoneal aortic thrombectomy.

A newborn infant with a history of umbilical artery catheterization had renal vascular hypertension and congestive heart failure. An abdominal ultrasound examination revealed aortic thrombosis extending from the celiac axis to the aortic bifurcation. Retroperitoneal aortic thrombectomy was performed without difficulty. The infant's hypertension and cardiac failure resolved. The retroperitoneal approach allowed excellent exposure of the aorta and avoided the postoperative gastrointestinal morbidity associated with a transperitoneal approach.

Voltage-tension relations in single frog atrial cardiac cells.

Voltage-clamp experiments were performed on isolated single frog (Rana catesbeiana or Rana pipiens) atrial cells to determine the voltage-contraction relations of the single cardiac cell. The contractile responses of the single cell associated with long duration (3 second) depolarizing steps consisted of a rise to peak (phasic) followed by a decay to a sustained contraction (tonic). These phasic-tonic type contractile responses could be obtained under conditions where membrane potential was well controlled along the entire length of the cell. Thus, the data obtained on the single cell indicate that the phasic-tonic contractile response is the characteristic contractile response of frog atrial tissue. The voltage dependence of the extent of relaxation to the tonic component following the peak of the contraction was affected dramatically by the intracellular sodium concentration. This result indicates that both the relaxation following peak contraction as well as the tonic contraction are related to calcium control via the sodium-calcium exchanger. The data also indicate that calcium entry via the inward calcium current is required for the contractile response to have a phasic component. These data indicate that calcium entry via the inward calcium current followed by the sodium-calcium exchanger first reducing and then maintaining the intracellular calcium level produces the characteristic phasic-tonic contractile response.

Congestive heart failure, hypertension, and hyperreninemia in bilateral Wilms' tumor: successful medical management.

Congestive heart failure is an unusual complication of the hyperreninemia of Wilms' tumors. Cases with bilateral tumors present a difficult management problem. This is a report of the successful medical management of a child with congestive heart failure secondary to hyperreninemia from bilateral Wilms' tumor. Hypertension and hyperreninemia were extensively documented. Their etiologic relation to the congestive heart failure was supported by the patient's improved cardiac function following specific renin-angiotensin blockade. With unilateral tumors, surgical excision corrects the hypertension; however, with large bilateral tumors, excision is out of the question. A unique feature of this case is the ability to control the blood pressure with saralasin. With subsequent antitumor therapy, renin concentrations decreased proportional to tumor size, and renin angiotensin blocking therapy could be discontinued.

Successful treatment of fetal supraventricular tachycardia with maternal digoxin therapy.

In a fetus with supraventricular tachycardia (SVT) and cardiac failure, normal sinus rhythm (NSR) was restored with maternal digoxin therapy at 26 weeks' gestation. The diagnosis of cardiac failure was based on ultrasound evidence of ascites and scalp edema. Cardiac failure was attributed to the persistent SVT. The infant remained in NSR and was delivered at 36 weeks' gestation because of persistent ascites. Intracardiac anatomy was normal. This case confirms the usefulness of prenatal ultrasound examinations in the diagnosis of fetal SVT and cardiac failure and illustrates the effectiveness and safety of transplacental digoxin therapy in the management of fetal SVT.

Depression of contractility following stretches and releases applied during contraction to single frog atrial cardiac cells.

The effects of stretches and releases on the contractile performance of isolated single frog atrial cells (Rana catesbeiana) were investigated. A stretch or release was imposed on the cell--either during a contraction (test) or before the onset of contraction (control)--and the contractile performance (length, velocity and force) of the test contraction was compared with that of the control contraction to determine whether the stretch or release imposed on the contracting cell altered the contractility of the cell. We found that the velocity of cell (and sarcomere) shortening for the remainder of the test contraction following either a stretch or release was markedly less than that occurring at the same time in the control contraction. This decreased velocity occurred even though the force in the test contraction was less than that in the control contraction and the sarcomere length was longer in the test contraction than in the control contraction. These results indicate that after a stretch or release imposed on the contracting cell, the force-velocity relationship at any given length and time is depressed than had the stretch or release not been imposed on the contracting cell. Thus, stretches and releases applied to the contracting single cardiac cell either produce a long-term depression in the contractility of the cell, or that the contractility at any given time and sarcomere length depends markedly on the history of the contraction.

Effect of external force on relaxation kinetics in single frog atrial cardiac cells.

The effects of external force on relaxation kinetics were investigated in isolated single frog (Rana catesbeiana) atrial cells. We found that force decay occurred at a maximum and constant rate for a significant portion of auxotonic relaxation, and this rate was linearly related to the peak force developed during auxotonic contraction. The slope of the linear relationship between the maximum rate of auxotonic force decay and peak auxotonic force was not affected by changes in the level of contractile activation produced by activating the cell with different stimulus durations. The rate of force change during auxotonic contraction and relaxation in the isolated cell is directly related to the average sarcomere velocity within the cell. Thus, the results indicate that during auxotonic relaxation the velocity of sarcomere extension is directly related to the peak auxotonic force, and sarcomere extension, during relaxation, is therefore affected by external force. The direct effect of external force on relaxation kinetics was confirmed by the observation that force changes imposed on the cell during relaxation immediately altered the velocity of the extending cell from any given length. However, data are also presented which demonstrate that rapid sarcomere extension occurs during relaxation under conditions where external forces are negligible. Thus, rapid sarcomere extension during relaxation does not require large external forces, and internal forces must play a role in sarcomere extension during relaxation. An explanation is given for these apparently contradictory results.