Assessment of the maximum voltage-guided technique for cavotricuspid isthmus ablation during ongoing atrial flutter.

OBJECTIVES: We aimed to test the maximum voltage-guided cavotricuspid isthmus (CTI) ablation technique during ongoing atrial flutter. BACKGROUND: Former pathological and electrophysiological studies clarified that the cavotricuspid isthmus is composed of distinct muscular bundles, which are responsible for the conduction of electrical activation. Based on this observation, a maximum voltage-guided ablation technique (MVGT) was developed. This technique was assessed during pacing from the coronary sinus and was reported to be a feasible method to reach bidirectional isthmus block without the need for a complete anatomic ablation line. METHODS: This was a prospective, randomized single center study. Twenty patients underwent CTI ablation during atrial flutter. In group I (10 pts) CTI ablation was performed with complete anatomical ablation line. In group II (10 pts) ablation was guided by the highest amplitude potentials on the CTI sequentially until bidirectional isthmus block was reached. The following parameters were compared: acute success rate, procedure time, fluoroscopy time, number of radiofrequency (RF) applications and total RF duration. RESULTS: In all patients, atrial flutter terminated during ablation. Bidirectional isthmus block could be achieved in all pts. Procedure time was shorter in group II (107 +/- 40 vs 68 +/- 19 min, p < 0.01). Significantly less fluoroscopy was used in group II (22.6 +/- 10.6 vs 12.1 +/- 3.8 min, p < 0.01). There were less RF applications in group II (27.1 +/- 21.5 vs 5.9 +/- 2.4, p < 0.001). CONCLUSIONS: (1) The major finding of this study is that MVGT is a feasible method even during ongoing atrial flutter. (2) Our data confirm that MVGT is an effective technique for CTI ablation with considerable decrease in procedure and fluoroscopy times.

Sympathetic denervation of the upper limb improves forearm exercise performance and skeletal muscle bioenergetics.

BACKGROUND: Sympathetic activation may limit exercise performance by restraining muscle blood flow or by negatively affecting skeletal muscle metabolic behavior. To test this hypothesis, we studied the effect of thoracoscopic sympathetic trunkotomy (TST) on forearm exercise duration, blood flow, and muscle bioenergetics in 13 patients with idiopathic palmar hyperhidrosis. METHODS AND RESULTS: Heart rate and beat-by-beat mean arterial pressure were recorded at rest and during right and left rhythmic handgrip before and 4 to 7 weeks after right TST. Forearm blood flow was measured bilaterally at rest and on the right during exercise. Right forearm muscle phosphocreatine content and intracellular pH were assessed by (31)phosphorus magnetic resonance spectroscopy. After right TST, exercise duration increased from 8.9+/-1.4 to 13.4+/-1.8 minutes (P<0.0001) with the right forearm and from 5.7+/-0.4 to 7.6+/-0.9 minutes (P<0.05) with the left (P<0.05 for the interaction between treatment and side). Right forearm blood flow at rest was 66% higher (P<0.01) after right TST, but this difference decreased as the exercise progressed. After right TST, a significant reduction occurred in muscle acidification and phosphocreatine depletion during ipsilateral forearm exercise. This was associated with a significantly reduced mean arterial pressure response to right handgrip, whereas the pressor response to left handgrip did not change. CONCLUSIONS: Sympathetic denervation of the upper limb significantly improves forearm skeletal muscle bioenergetics and exercise performance in patients with idiopathic palmar hyperhidrosis.

Reduced pain during baroreceptor stimulation in patients with symptomatic and silent myocardial ischaemia.

OBJECTIVE: Baroreceptor activation has been shown to reduce pain, and the accumulation of such pain reduction has been implicated in the operant learning (under certain circumstances) of hypertension. The current study is an examination of differences in the pain dampening effects of baroreceptor activity in patients with symptomatic and asymptomatic myocardial ischaemia. The objective was to determine whether there are differences between patients with symptomatic and silent myocardial ischaemia with respect to their antinociceptive response to baroreceptor stimulation, and, if so, whether these differences could be related to the absence of angina pectoris pain in patients with silent myocardial ischaemia. METHODS: Sensory detection and electrical pain thresholds were compared in nine symptomatic and 10 asymptomatic patients with replicable myocardial ischaemia during PRES (phase related external suction) carotid baroreceptor manipulation in which the pressure inside a neck cuff was phase locked in time to the R wave of the ECG and negative pressure was applied during either systole or diastole. Tourniquet pain thresholds were also determined. RESULTS: It was found that (1) external baroreceptor manipulation had no effect on detection thresholds; (2) painful stimuli were judged by both symptomatic and asymptomatic patients as less intense when delivered during maximum baroreceptor activity; (3) symptomatic and asymptomatic patients did not differ in their sensory detection thresholds; and (4) asymptomatic patients had significantly higher ischaemic (tourniquet) pain thresholds than symptomatic patients. CONCLUSIONS: The results indicate that baroreceptor activity can modify the intensity of painful stimuli. The degree to which baroreceptor manipulation affects pain does not appear to differ between patients with painful and silent myocardial ischaemia. Thus the baroreceptor dependent pain inhibition effects seems not to be responsible for the higher ischaemic pain threshold found in the silent myocardial ischaemia group.

QT interval dynamics and heart rate variability preceding a case of cardiac arrest.

A 71 year old man with hypertensive heart disease and chronic renal failure was wearing a Holter monitor when he had a cardiac arrest. He had ventricular fibrillation (VF) and died despite prompt resuscitation. In the 15 minutes preceding the VF there was a sudden increase in heart rate, followed by a brief period of atrial fibrillation leading to ventricular tachycardia, which in turn rapidly degenerated into VF. The QT interval and heart rate variability were studied half hourly over the seven hours preceding the cardiac arrest, using a computerised Holter system. A further detailed analysis was performed over the final hour before the cardiac arrest. An abrupt increase in the steepness of the QT/RR slope, a prolonged QTc, and a reduction in the heart rate variability were observed in the interval that immediately preceded the onset of the terminal rhythm disturbance.

Lipophilic versus hydrophilic beta(1) blockers and the cardiac sympatho-vagal balance during stress and daily activity in patients after acute myocardial infarction.

OBJECTIVE: To compare the effects of a lipophilic and a hydrophilic beta(1) blocker on cardiac sympatho-vagal balance during daytime activity and stress in patients four to six weeks after myocardial infarction. DESIGN: Randomised, double blind, crossover study comparing the effect of atenolol (50 mg once daily) with metoprolol CR (100 mg once daily) with treatment periods of four weeks. SETTING: Large teaching hospital. PATIENTS: 50 patients (45 male, 5 female, age range 40 to 75 years), four to six weeks after an acute myocardial infarction. METHODS: At the end of each treatment period the 24 hour heart rate variability, heart rate variability power spectra during head up tilt and mental stress, baroreflex sensitivity, and exercise performance were evaluated. RESULTS: During daytime activity and during orthostatic and mental stress, both heart rate and the ratio between the low and high frequency spectral components of the heart rate variability were significantly lower with atenolol. Conversely, there was no difference between treatments in baroreflex sensitivity and resting plasma catecholamines. Exercise duration and peak oxygen consumption did not differ between treatments, but the heart rate during submaximal and peak exercise was significantly lower with atenolol. CONCLUSIONS: At the doses used in this study, atenolol achieved greater beta(1) adrenergic blockade than metoprolol CR and this was associated with significant inhibition of vagal withdrawal during stress. This suggests that peripheral blockade of beta(1) adrenergic receptors may be more important than central blockade in preventing stress induced vagal withdrawal in patients after myocardial infarction.

Baroreceptor stimulation: pain perception and sensory thresholds.

Baroreceptor activity has been implicated in the modulation of pain. Sensory detection thresholds and pain ratings were measured in a group of 28 men during carotid baroreceptor manipulation with the PRES (phase-related external suction) neck suction technique. Brief, cardiac phase-related electrical impulses were delivered intracutaneously to the finger. The results indicate that minimum baroreceptor activity was associated with more severe pain, but had no effect on sensory detection threshold. The results are discussed in terms of the learned model of hypertension.

[Association of AV reciprocating tachycardia, using a concealed bundle of Kent, and paroxysmal atrial fibrillation in neurocardiogenic syncope]. / Neurocardiogen reflex-syncope, rejtett Kent-köteget felhasználó AV-reciprok tachycardia és paroxysmalis pitvarremegés együttes elöfordulása.

A case of neurocardiogenic syncope is reported in which both AV-reciprocating tachycardia due to a concealed retrogradely conducting posteroseptal bypass tract and paroxysmal atrial fibrillation were observed. In connection with this case, attention is paid to the difficulties of differential diagnosis and to the pathophysiological correlations concerning the occurrence of neurocardiogenic/vasovagal reflex syncope and cardiac arrhythmias. A prolonged period of freedom from syncope and tachycardia was achieved by means of drug treatment, through the combined administration of disopyramide, bisoprolol and theophylline.

[Micturition syncope]. / Micturitiós syncope.

The micturition syncope is a special manifestation of the so called "situational syncopes". These reflex syncopes share efferent mechanisms with the neurocardiogenic, or vasovagal syncope. A case of a patient is reported, who presented with micturition syncope. The patient's tendency for vasovagal syncope was documented by a positive tilt table test. The uniform premonitory symptoms preceding the two fainting attacks indicated the relation between the episodes. The authors review the literature of the micturition syncope, and discuss the potential pathomechanisms.

[Diagnosis of femoral pseudoaneurysm and factors contributing to its incidence after heart catheterization]. / Szívkatéterezést követöen létrejött femoralis álaneurysma diagnózisa és a kialakulásában szerepet játszó tényezök.

Two-hundred patients who underwent heart catheterization between 30 November 1989 and 30 September 1990, were followed up to establish the frequency of the vascular complications (mainly femoral pseudoaneurysm) of the procedure. Factors were evaluated which may promote the occurrence of femoral pseudoaneurysms. This complication was diagnosed in 6 cases. Two-dimensional and Doppler echocardiography (conventional and colour-coded) played an important role in the diagnosis. Systemic hypertension, anticoagulant therapy, obesity and technical difficulties (multiple punctures and catheter guidance problems) proved to be factors promoting femoral pseudoaneurysms. Serial echocardiograms revealed a tendency to spontaneous healing even in cases of relatively large pseudoaneurysms.

[Continuous non-invasive blood pressure monitoring in the diagnosis of pacemaker syndrome]. / Folyamatos, noninvazív vérnyomásmérés a pacemaker szindróma diagnózisában.

The drop in blood pressure coinciding with the atrioventricular dyssynchrony plays an important role in the genesis of pacemaker syndrome. The diagnosis is often based on continuous blood pressure recording. Formerly the continuous blood pressure monitoring could only be performed by invasive methods. The authors demonstrate the feasibility of a new non invasive continuous blood pressure recorder, the Finapres 2300, by presenting illustrative case reports. The authors recommend more widespread use of non invasive haemodynamic monitoring for the diagnosis of pacemaker syndrome.

[Systemic thrombolysis in acute obstruction of an artificial valve]. / Systemás thrombolysis acut mübillentyü obstructióban.

Prosthetic valve thrombosis is a characteristic, but fortunately not frequent complication of surgical valve replacement. Its occurrence may lead to haemodynamic catastrophe. Three cases involving prosthetic valve thrombosis are presented. Two patients suffered from thrombosis after tricuspid valve replacement (St. Jude Medical), while the third occurred after mitral valve replacement (Sorin). In the acute phase, systemic thrombolysis was initiated (2 MU Streptokinase during 22-28 hours). The obstruction of one of the tricuspid valves and the mitral valve was eliminated. Lysis of the other tricuspid valve was not complete, but it helped the patient to survive the acute phase until reoperation. Embolization occurred in the inferior extremity after thrombolysis of the mitral prosthetic valve, but it was cured. Two-dimensional and Doppler echocardiography (conventional and colour-coded) played an important role in the diagnosis of the obstruction and in the follow-up of the effectivity of thrombolysis. Systemic thrombolysis may be a lifesaving procedure in acute prosthetic valve thrombosis. In spite of the potentially dangerous complications, it has to be attempted.

[Judging the severity of regurgitation in acquired heart defects using color-coded Doppler echocardiography]. / Regurgitatiók súlyossági fokának megítélése színkódolt Doppler echocardiographiával, szerzett vitiumokban.

In the study, 139 valvular regurgitations of 120 patients (55 mitral and 84 aortic regurgitations) were investigated and compared by means of colour flow mapping and heart catheterization. During the echocardiographic examination, the length and width of the regurgitant jets were measured and the jet area was planimetered besides the subjective grades. The above parameters were correlated with the angiographic grades. Good agreement was found between the results of the two methods. As concerns the different parameters of the regurgitant jets in mitral regurgitation, the most severe (grade IV) category was easily distinguished from the others, while in aortic regurgitation all four categories were differentiated by colour flow mapping. These measurements indicated that colour-coded Doppler echocardiography is a suitable tool for detection of the severity of valvular regurgitations in a noninvasive way.

[Doppler echocardiography in the examination of normally functioning artificial mitral and aortic valves]. / Normálisan müködö mitralis és aorta mübillentyük vizsgálata Doppler echocardiographiával.

Patients with prosthetic valves were investigated by Doppler echocardiography in 902 cases between November 1987 and February 1990. The parameters of 209 of 344 mitral and 258 of 299 aortic prosthetic valves were evaluated. No significant correlation was found between the type of aortic or mitral prosthetic valves and the measured gradient. As concerns the size of the valve and the measured gradient, a close correlation for aortic valve replacement was detected. For a normally functioning mitral prosthetic valve, a maximum early diastolic velocity of less than 2 m/s (16 mm Hg gradient) and a pressure half-time of less than 130 ms (mitral valve area 1.8 cm2) were characteristic. In cases of aortic valve replacements, the maximum velocity was less than 3 m/s (36 mm Hg gradient), except for the small-diameter valves. More than 95% of the cases met these criteria. (Even if small-diameter valves were included, a maximum velocity of more than 3 m/s occurred only in 8.9%.) Doppler echocardiography is a suitable tool for detecting normal prosthetic valve function, while colour Doppler allows the optimal alignment of jet direction and Doppler beam.

[Defecation syncope following pacemaker implantation]. / Defecatiós syncope jelentkezése pacemaker beültetést követóen.

A case of syncope is reported, where hemodynamic responses compatible with pacemaker syndrome occurred during defecation. A 73 year old female received a VVI pacemaker for complete heart block. Subsequently she sustained repeated episodes of defecation syncope. Hemodynamic investigations revealed an abnormal blood pressure drop occurring at the overshoot phase of the Valsalva maneuver in association with alternation of sinus and pacemaker rhythm. This modified Valsalva response in the presence of contributing factors, such as hypovolemia and nitroglycerin therapy manifested as defecation syncope. The abnormal condition was treated by eliminating the contributing factors, and by programming a low pacemaker frequency, thus precluding sinus-pacemaker alterations.

[Management of severe orthostatic hypotension by head-up-tilt posture and administration of fludrocortisone]. / Súlyos fokú orthostaticus hypotonia kezelése "head-up-tilt" fektetéssel és fludrocortisonnal.

A case of a 66-year-old man with recurrent episodes of syncope is reported. The syncopal attacks started five years ago in sitting and standing positions. At the time of admission the fainting attacks occurred 2-3 times per day. The diagnostic tests revealed severe orthostatic hypotension. The medical treatment was started with salt enriched diet and fludrocortisone. The efficacy of the therapy was tested by using the tilt table test with a self developed computer system consisting of a non-invasive finger blood pressure monitor and ECG. The orthostatic tolerance improved with the medical therapy, however remained unsatisfactory for the patient's daily activity. Though the patient had less frequent symptoms, he had still sustained episodes of recurrent syncopes. The medical therapy was than combined with sleeping in the 15 degrees head-up-tilt position. The repeat tilt table test was performed two weeks after initiation of the 15 degrees head-up-tilt sleeping. The orthostatic tolerance was markedly improved. The patient became free of symptoms and during a four-week follow-up his condition remained stable. At the control the patient reported about deterioration of his symptoms as a result of the discontinuation of sleeping in "head-up-tilt" position for two weeks. The objective signs leading to aggravate his symptoms was documented by the tilt table test. We reinstituted the "head-up-tilt" sleeping in his therapeutic management.

[Cardiovascular autonomic regulation following orthoptic heart transplantation]. / A cardiovascularis autonóm reguláció vizsgálata orthotopicus szívátültetést követóen.

Numerous recent observations have indicated autonomic reinnervation of transplanted human hearts. In order to assess autonomic regulation 5 patients were studied 1 to 5 years following cardiac transplantation. A series of tests were performed, including blood pressure and ECG recordings on rest, during 15/min patterned breathing, isometric handgrip exercise, and Valsalva manoeuvre. The time domain indices (SDRR, pNN50, rMSSD) and the frequency domain indices of heart rate variability were also studied. Among the five patients under study only one exhibited features compatible with both sympathetic and parasympathetic reinnervation. Traditional autonomic reflex tests and the analysis of time and frequency domain indices of HRV serve as simple tool in primary assessment of cardiac reinnervation.

Left atrial and left atrial appendage function in paroxysmal atrial fibrillation.

PURPOSE: In patients with paroxysmal atrial fibrillation (PAF) little information is available about left atrial (LA)function, and there is less information about LA appendage (LAA) function, and about their relations. METHODS AND RESULTS: 46 patients were selected for catheter ablation (CA) because of nonvalvular PAF.Transthoracic, tissue Doppler and transoesophageal echocardiography was performed before CA. LA volumes and volume index (LAVI) were calculated. LA function was assessed by LA filling fraction (LAFF), LA emptying fraction (LAEF), systolic fraction of pulmonary venous flow (PVSF) and late diastolic velocities of mitral annulus(Aa,, A5at) LAA function was assessed by peak LAA emptying flow velocity (PLAAEFV). Diastolic dysfunction(DD) was also assessed. Dilated LAVI in 32, LA dysfunction in 20, DD with elevated LV filling pressure in 19 patients was found. Aa,at and Aa,p correlated with LAFF (r:0.53; p<0.001 and r:0.43; p<0.05), LAEF (r:0.51;p<0.001 and r:0.63; p<0.001), PVSF (r:0.49; p<0.001 and r:0.46; p<0.005) and PLAAEFV (r:0.58; p<0.001 and r:0.45; p<0.01). CONCLUSIONS: In PAF patients Aa velocity is useful to assess LA function and correlates positively with other TTE derived LA functional parameters and LAA function by TEE derived PLAAEFV.