Supraventricular tachycardia treatment

supraventricular tachycardia treatment magas vérnyomás a tachycardia hátterében

We also evaluated the effects of aprindine on experimental AF in isolated guinea-pig hearts. Electrophysiological analyses including the supraventricular tachycardia treatment of tails test revealed that aprindine preferentially inhibits IKr rapidly activating component but not IKs slowly activating component.

ACh with the IC50 values of 0. In atrial cells stimulated at 0. The drug also reversed the carbachol-induced action potential shortening in a concentration-dependent manner. In isolated hearts, perfusion of carbachol 1 μM shortened monophasic action potential MAP and effective refractory period ERPand lowered atrial fibrillation threshold.

We conclude the efficacy of aprindine against AF may be at least in part explained by its inhibitory effects on IKr and Supraventricular tachycardia treatment. Therefore the insight is growing that it may not be sufficient to control the ventricular rate during AF, but it may be necessary to cure AF itself in order to prevent the serious adverse outcome.

Many investigators were devoted to the mechanisms of AF, and the wavelet hypothesis for AF has emerged from the mapping studies magas vérnyomás 1 stádiumú tünetek experimental AF Allessie et al.

supraventricular tachycardia treatment magas vérnyomás ásványvíz

It was established that several wavelets and the shortened length of wavelet, i. As the wavelength is the product of refractory period and conduction velocity, the pharmacological strategy for prevention of AF is to prolong supraventricular tachycardia treatment refractory periods or to increase conduction velocity.

Modified Valsalva manoeuvre for supraventricular tachycardia

ACh are involved in the repolarization of the action potential in atrial cells Carmeliet, Class I antiarrhythmic drugs have been subdivided according to their effects on action potential duration APD : class Ia lengthens the duration, Ib shortens it, and Ic supraventricular tachycardia treatment no effects or minimally increases APD.

Since aprindine hydrochloride hereafter abbreviated as aprindine was demonstrated to depress the maximum upstroke velocity of the action potential Vmax and abbreviate APD in Purkinje and ventricular tissues Verdonck et al. However, aprindine has been shown to be effective against not only ventricular arrhythmias but also supraventricular tachycardia treatment arrhythmias including AF Kesteloot et al.

Since aprindine potently inhibited IK. ACh and the rapid component of IK IKr in this study, we also evaluated the effects of aprindine on the experimental AF in Langendorff-perfused guinea-pig hearts.

supraventricular tachycardia treatment szív egészségügyi menük

Single atrial cells of the guinea-pig heart were isolated by an enzymatic dissociation method, as described previously Tohse et al. The heart was removed from open chest guinea-pigs — g anaesthetized with pentobarbitone sodium and mounted on a modified Langendorff perfusion system for retrograde perfusion of the coronary circulation with a normal HEPES-Tyrode's solution.

Atrial tissue was cut into small pieces in the modified KB solution and gently shaken to dissociate cells. Whole-cell membrane currents were recorded by the patch-clamp method Hamill et al.

The temperature of supraventricular tachycardia treatment external solution was kept constant at Patch pipettes were made from glass capillaries with a diameter of 1.

They were filled with an internal solution, and their resistance was 2—4 MΩ. After the giga-ohm seal between the tip of the electrode and the cell membrane was established, the membrane patch was disrupted by more negative pressure to make the whole-cell voltage-clamp mode.

Recordings were filtered at 1 kHz bandwidth, and series resistance was compensated. In addition, the envelope of tails test was performed. The ratio of tail current of IK IK,tail to the time-dependent current activated during depolarizing pulses of various durations IK,depo was determined in the absence and presence of aprindine.

The IK,tail was measured as a peak current which was actually recorded upon the clamp back to the holding potential. The deactivation kinetics of IK was also analysed by using an exponential fitting.

The exponential analysis of IK,tail after ms and 5 s depolarizing pulses was performed by fitting the deactivation kinetics to an equation of the following form; where τ1 and τ2 supraventricular tachycardia treatment fast and slow time constants, A1 and A2 are the amplitudes of each component and A0 is the baseline value. The curve-fitting procedure used a non linear least-squares algorithm. We used two exponentials fitting for IK,tail analysis before and after aprindine because we could obtain better least square residual values.

The IK. Effects of various concentrations of aprindine on the IK. ACh activated in three different ways were examined. To calculate per cent inhibition of IK. Current-clamp experiments were also performed in the whole-cell recording mode at 36±1°C.

[ECG pearl: Valsalva maneuver terminated ventricular tachycardia].

External and pipette solutions were the same as those used to record the carbachol-induced IK. The cells were supraventricular tachycardia treatment by passing 2 ms currents through the pipette at a rate of 0. After a stabilization of action potential configuration, effects of aprindine on the action potential in the presence or absence of carbachol 1 μM were evaluated.

Isolated heart study The heart was removed from the open-chest guinea-pigs — g anaesthetized with pentobarbitone sodium. The aorta was cannulated and perfused at a constant pressure mmH2O of normal Tyrode's solution. The right atrium was stimulated with an external bipolar silver electrode.

The stimuli were rectangular pulses of 2-ms duration at twice the diastolic threshold, delivered from an electronic stimulator model SEC, Nihon Kohden. The left atrial electrograms were recorded using an additional bipolar suction electrode for measure of monophasic action potentials MAP with a diameter 2. Atrial effective refractory period ERP was determined using the standard extrastimulus technique.

After every eighth basic right atrial stimulus S1S1 msan extrastimulus S2 was delivered with a shortening of the coupling interval S1S2 in 5-ms steps until the S2 produced no atrial activity.

A PSVT helynyilvántartása. Paroxysmal Supraventricular Tachycardia (PSVT) nyilvántartás.

Conduction time CT from the right to the left atrium was measured as the time from the pacing spike to the first upstroke of left atrial action potential on the oscilloscope model VC, Nihon Kohden. Atrial fibrillation threshold AFT was measured by rapid atrial electrical stimulation according to supraventricular tachycardia treatment method of Inoue et al.

The supraventricular tachycardia treatment current consisted of a train of 50 square wave pulses, 2 ms in duration at a frequency of 50 Hz for a duration of 1 s.

supraventricular tachycardia treatment lehetséges-e hipertóniával kötelet ugrani

The pulse train was delivered to the right atrium after every eighth basic paced beat. The current was increased in increments of 0. The AFT was defined as the minimum amount of current required to induce AF which was sustained for at least 30 s.

Sustained AF was terminated readily by perfusing normal Tyrode's solution. The stimulator used in this study was unable to deliver a current greater than 11 mA. Initial measurements were made during perfusion with Tyrode's solution control values. The same measurements were then repeated 10 min after changing to a Tyrode's solution containing carbachol 1 μM and 10 min after the perfusion of the normal Tyrode's solution supraventricular tachycardia treatment carbachol 1 μM and aprindine 3 μM.

Nifedipine was dissolved in ethanol as a stock solution of 10 mM.

Inappropriate sinus node tachycardia after ablation treatment of AV-nodal reentry tachycardia

The final concentration of ethanol was less than 0. It was confirmed that this concentration of ethanol had no influence on the membrane currents. Other drugs were dissolved in distilled water. Statistics All values are presented mean±s. P value of less than 0. Representative supraventricular tachycardia treatment in the membrane currents and summarized data of current-voltage relations after aprindine 3 μM are shown in the left and right panels of Figure 1respectively.

We selected a concentration of aprindine, 3 μM, because this concentration of aprindine was reported to suppress Vmax in isolated ventricular supraventricular tachycardia treatment Kodama et al. Aprindine slightly decreased ICa, but the changes were statistically insignificant. These findings suggest that aprindine inhibits IK in guinea-pig atrial cells.