Unruptured aneurysm of the left sinus of Valsalva compressing the left main coronary artery: successful percutaneous treatment.

Aneurysm of the left sinus of Valsalva is an extremely rare entity. It may be asymptomatic and incidentally discovered, or may be symptomatic and manifest acutely with compression of adjacent cardiac structures. Encasement of the left main coronary artery by such an aneurysm is a recognized but infrequent complication that can lead to severe coronary insufficiency. Surgical decompression of the left main coronary artery is the standard treatment for such conditions. We describe a patient presenting with extrinsic compression of the left main coronary artery by a large unruptured aneurysm of the left sinus of Valsalva occurring 4 months after unsuccessful surgical repair. Since reoperation was considered high-risk for the patient, successful fractional flow reserve- and intravascular ultrasound-guided percutaneous treatment of the left main coronary artery was performed with implantation of one bare-metal stent.

Evaluation of post-surgical cognitive function and protein fingerprints in the cerebro-spinal fluid utilizing surface-enhanced laser Desorption/Ionization time-of-flight mass-spectrometry (SELDI-TOF MS) after coronary artery bypass grafting: review of proteomic analytic tools and introducing a new syndrome.

Cognitive dysfunction following surgery is a common complication, which increases the incidence of other co-morbid conditions, hospital and health-care costs. The reported rate of the occurrence of post-operative cognitive decline varies with different studies, depending on population profile, type of surgery, definition of cognitive disorder and detection methods, design of study, etc. It remains unclear whether these psychiatric signs and symptoms are direct results of the effects of surgery or general anesthesia. Nonetheless they are more frequent after cardiac surgery and are likely to be multi-factorial, but the patho-mechanisms are not yet fully characterized. This communication provides a synopsis of proteomics tools and delineates novel SELDI-TOF results to evaluate biomarkers in this regard. Presented for the first time is a classification of the clinically relevant forms of post-operative cognitive decline with the advent of a novel subclass.

Modulation of cardiac contractility through endothelin-1 release and myocardial mast cell degranulation.

The aim of this study was to outline the consequences of a hypertonic saline-dextran-40 (HSD) infusion-induced peripheral flow stimulus on the ventricular function in closed-chest, pentobarbital-anesthetized dogs. We hypothesized that HSD-induced elevation in endothelin-1 (ET-1) and nitric oxide (NO) release can have a role in myocardial contractile responses; and that cardiac mast cells (MC) degranulation may be involved in this process. The consequences of disodium cromoglycate (a MC stabilizer) or ETR-p1/fl peptide (an endothelin-A receptor antagonist) treatment were evaluated. A 4 ml/kg iv HSD40 infusion significantly increased cardiac index and myocardial contractility, and resulted in a decreased peripheral resistance. The postinfusion period was characterized by significant plasma NO and ET-1 elevations, these hemodynamic and biochemical changes being accompanied by a decreased myocardial ET-1 content, NO synthase activity and enhanced myocardial MC degranulation. Disodium cromoglycate treatment inhibited the HSD40-induced elevations in myocardial contractility and MC degranulation, and similar hemodynamic changes were noted after treatment with ETR-p1/fl peptide, together with a normalized myocardial myocardial ET-1 content, NO synthesis and a significant reduction in MC degranulation. These results indicate that peripheral NO and ET-1 release modulates the cardiac contractility through myocardial ET-A receptor activation and MC degranulation.

Components of respiratory resistance monitored in mechanically ventilated patients.

The interrupter technique is commonly adopted to monitor respiratory resistance (Rrs,int) during mechanical ventilation; however, Rrs,int is often interpreted as an index of airway resistance (Raw). This study compared the values of Rrs,int provided by a Siemens 940 Lung Mechanics Monitor with total respiratory impedance (Zrs) parameters in 39 patients with normal spirometric parameters, who were undergoing elective coronary bypass surgery. Zrs was determined at the airway opening with pseudorandom oscillations of 0.2-6 Hz at end inspiration. Raw and tissue resistance (Rti) were derived from the Zrs data by model fitting; Rti and total resistance (Rrs,osc=Raw+Rti) were calculated at the actual respirator frequencies. Lower airway resistance (Rawl) was estimated by measuring tracheal pressure. Although good agreement was obtained between Rrs,osc and Rrs,int, with a ratio of 1.07+/-0.19 (mean+/-SD), they correlated poorly (r2=0.36). Rti and the equipment component of Raw accounted for most of Rrs,osc (39.8+/-11.9 and 43.0+/-6.9%, respectively), whereas only a small portion belonged to Rawl (17.2+/-6.3%). It is concluded that respiratory resistance may become very insensitive to changes in lower airway resistance and therefore, inappropriate for following alterations in airway tone during mechanical ventilation, especially in patients with relatively normal respiratory mechanics, where the tissue and equipment resistances represent the vast majority of the total resistance.

The cellular electrophysiologic effect of a new amiodarone like antiarrhythmic drug GYKI 16638 in undiseased human ventricular muscle: comparison with sotalol and mexiletine.

The cellular electrophysiologic effect of GYKI 16638, a new antiarrhythmic compound was studied and compared with that of sotalol and mexiletine in undiseased human right ventricular muscle preparation by applying the conventional microelectrode technique. GYKI 16638 (5 microM), at stimulation cycle length of 1000 ms, lengthened action potential duration (APD(90)) from 338.9 +/- 28.6 ms to 385.4 +/- 24 ms (n = 9, p > 0.05). This APD lengthening effect, unlike that of sotalol (30 microM), was rate-independent. GYKI 16638, contrary to sotalol and like mexiletine (10 microM), exerted a use-dependent depression of the maximal rate of depolarization (V(max)) which amounted to 36.4 +/- 11.7% at cycle length of 400 ms (n = 5, p < 0.05) and was characterised with an offset kinetical time constant of 298.6 +/- 70.2 ms. It was concluded that GYKI 16638 in human ventricular muscle shows combined Class IB and Class III antiarrhythmic properties, resembling the electrophysiological manifestation seen after chronic amiodarone treatment.

The slow component of the delayed rectifier potassium current in undiseased human ventricular myocytes.

OBJECTIVE: The purpose of this study was to investigate the properties of the slow component of the delayed rectifier potassium current (I(Ks)) in myocytes isolated from undiseased human left ventricles. METHODS: The whole-cell configuration of the patch-clamp technique was applied in 58 left ventricular myocytes from 15 hearts at 37 degrees C. Nisoldipine (1 microM) was used to block inward calcium current (I(Ca)) and E-4031 (1-5 microM) was applied to inhibit the rapid component of the delayed rectifier potassium current (I(Kr)). RESULTS: In 31 myocytes, an E-4031 insensitive, but L-735,821 and chromanol 293B sensitive, tail current was identified which was attributed to the slow component of I(K) (I(Ks)). Activation of I(Ks) was slow (tau=903+/-101 ms at 50 mV, n=14), but deactivation of the current was relatively rapid (tau=122.4+/-11.7 ms at -40 mV, n=19). The activation of I(Ks) was voltage independent but its deactivation showed clear voltage dependence. The deactivation was faster at negative voltages (about 100 ms at -50 mV) and slower at depolarized potentials (about 300 ms at 0 mV). In six cells, the reversal potential was -81.6+/-2.8 mV on an average which is close to the K(+) equilibrium potential suggesting K(+) as the main charge carrier. CONCLUSION: In undiseased human ventricular myocytes, I(Ks) exhibits slow activation and fast deactivation kinetics. Therefore, in humans I(Ks) differs from that reported in guinea pig, and it best resembles I(Ks) described in dog and rabbit ventricular myocytes.

[Surgical treatment of giant basilar artery aneurysm with induced hypothermia and circulatory arrest]. / Arteria basilaris óriásaneurysma mútéti kezelése hypothermiában végzett keringésmegállítás alatt.

Surgical management of giant and complex posterior circulation aneurysms continues to be a technically difficult task with high operative morbidity. To minimize morbidity we have used cardiopulmonary bypass and circulatory arrest for the treatment of a giant basilar aneurysm. A 48-year-old woman presented with sudden headache. Magnetic resonance angiography revealed a giant basilar aneurysm. On the 2nd hospital day she developed right sided hemiparesis and cranial nerve deficits as a result of the second rupture of the aneurysm. The aneurysm was successfully treated and no significant neurological complications were related to this technique. This initial experience indicates that patients with giant posterior circulation aneurysm that cannot be treated using conventional techniques might benefit from a surgical approach that included the use of deep hypothermic circulatory arrest.

Modified Blalock-Taussig shunt using allograft saphenous vein: six years' experience.

BACKGROUND: The occurrence of life-threatening late infectious complications after the use of expanded polytetrafluoroethylene conduits as modified Blalock-Taussig shunts prompted us to apply allograft saphenous veins instead. METHODS: In 23 cyanotic patients (age, 1 week to 18 years) allograft saphenous veins were used for performing Blalock-Taussig shunts from July 1989 onward. Veins stored in Hank's solution were implanted in 8 patients and cryopreserved ones in 15. All patients were followed up regularly up to 15 months. RESULTS: There were two early and two late deaths: none were related to shunt occlusion. Clinical, angiographic, and echocardiographic studies proved that, except for one early occlusion, all shunts were patent and functioning well after an average of 41 months. Donor cells disappeared 1 to 3 days after implantation, and several months after the operation both the wall and the luminal surface of the grafts were repopulated with cells possibly of recipient origin. No difference was found between veins stored in Hank's solution only and cryo-preserved grafts, concerning clinical outcome and histology. CONCLUSIONS: Allograft saphenous veins function well as modified Blalock-Taussig shunts at least up to 6 years. Owing to the good results and lack of complications their clinical use is recommended.

[Modified Blalock-Taussig shunt using a saphenous vein allograft. Five-year experience]. / Módosított Blalock-Taussig-shuntök allograft vena saphena alkalmazásával. Ot év tapasztalatai.

From July 1989 to June 1994 23 modified Blalock-Taussig shunts were performed using allograft saphenous veins. Veins stored in Hank's solution were implanted in 8, and cryopreserved ones were used in 15 cases. No operative death, bleeding, or infectious complication has occurred. There were 2 early and 2 late deaths, none was related to shunt occlusion. Clinical, angiographic and echocardiographic investigations proved that the rest of the shunts are still patent and functioning well after an average of 30 months follow up. Histological studies showed that donor cells have been replaced after several months with recipient cells both in the wall and at the luminal surface of the grafts. No difference was found between veins stored in Hank's solution and cryopreserved grafts concerning clinical outcome and histology.

Measurement of resistance versus flow in assessing efficiency of aortocoronary bypass grafts.

Measurement of flow in saphenous bypass grafts with an electromagnetic flowmeter is complicated and poorly reproducible. Since coronary flow is largely dependent on variable factors the stable value of resistance seems more appropriate for comparison. A simple method has been developed for intraoperative measurement of resistance in the respective coronary bed. Pressure is recorded in the saphenous graft by an electromanometer during continuous flushing with known amounts of blood, and resistance is calculated instantaneously. The procedure is very simple and takes less than one minute. The quality of the saphenous vein itself can be assessed simultaneously by the same method. Resistances were measured during coronary surgery in over 500 saphenous grafts. The results were highly reproducible and comparable. Excellent flows can be expected if resistance is below 200 Peripheral Resistance Units (PRU); if this is over 800 PRU flow is very poor.