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Biomedical subjects

G Satullo

Publications and source records attributed to G Satullo.

At least 37 records · Page 2Linked to original sources
PubMed1989

Trifascicular block with asynchronous intraventricular recovery and "supernormal" AV conduction.

The authors present a case of trifascicular block: complete right bundle branch block, tachycardia-dependent left anterior hemiblock, and bradycardia-dependent left posterior hemiblock. There is, in addition, a complicating independent AV junctional rhythm that is in most instances not affected by the conducted sinus impulses. Occasionally, however, this focus is discharged by very early sinus impulses that are unexpectedly conducted to the ventricles (a manifestation of "supernormal" conduction). A complex electrocardiographic pattern results from the interplay of the aforementioned mechanisms.

Atrioventricular Node↗
PubMed1989

Concealed ventricular hexageminy.

The authors report a case of concealed ventricular hexageminy in which, with a few exceptions, extrasystoles were separated by sinus beats conforming to the formula 6n - 1. Whenever an exception to this formula occurs, the intervening beats are not all of sinus origin, but include also a ventricular extrasystole that is different from those occurring in hexageminal distribution. The pattern is explained by a parasystolic rhythm modulated by sinus impulses, assuming a 3:1 ratio between the parasystolic cycle and the sinus cycle. Such a ratio would have to be associated with a trigeminal or concealed trigeminal distribution. There is, however, a 2:1 ectopic-ventricular block, leading to a change of the ectopic distributional pattern from the expected concealed trigeminy to that of the concealed hesageminy.

Aged↗
PubMed1989

Modulated parasystole complicating permanent ventricular pacing: the different influence of spontaneous and paced impulses upon the parasystolic rhythm.

A case of modulated ventricular parasystole observed in a patient with a VVIM pacemaker is reported. Analysis reveals that the electronic influence (modulation) effected upon the parasystolic focus by the sinus impulses is different from that exerted by the paced impulses. Furthermore, fusion beats reflect an intermediate modulating effect according to the prevalence of the sinus or the paced wavefront.

Aged↗
PubMed1989

[A-V conduction in atrial flutter. Electrocardiographic study].

One hundred and twenty-nine cases of atrial flutter were analyzed to assess the A-V conduction. The R-R intervals, the A-V conduction ratio, and the F-R intervals were measured in each case. Conduction in atrial flutter was defined either as constant or as variable depending on whether the A-V conduction ratio was fixed or variable. Furthermore, atrial flutter was defined as regular whenever the R-R intervals were mathematically related to each other, any interval being a multiple of the F-F cycle. On the other hand, atrial flutter was defined as irregular when the R-R cycles did not reflect a precise mathematical relationship. The R-R intervals in irregular atrial flutter were not exactly multiples of the F-F cycle. This was because the F-R intervals were variable. Sixty-five cases of atrial flutter had constant A-V conduction, whereas 64 cases were associated with variable A-V conduction. Eighty-eight per cent of cases with constant conduction were regular. On the contrary, 91% of cases with variable A-V conduction were irregular. These data reflect a relationship between the constancy of the A-V conduction ratio and the regularity of the R-R intervals. Several mechanisms were identified as being responsible for atrial flutter irregularity. Alternation of the F-R intervals was the most frequent mechanism leading to irregularity of atrial flutter with constant A-V conduction. Alternating Wenckebach periodicity was the most common cause of irregularity in atrial flutter with variable conduction ratio. Concealed conduction of blocked impulses was also frequently involved in determining atrial flutter irregularity.

Atrial Flutter↗
PubMed1988

Mobitz type II delay.

Mobitz type II second-degree block manifests with several consecutive impulses conducted with a constant conduction time that are followed by block. This study reflects an entirely new concept of the Mobitz type II phenomenon, wherein consecutive impulses have constant conduction times, but instead of being followed by a block of conduction, are in fact followed by a conduction delay. The diagnosis of this manifestation at the atrioventricular (AV) junction is made by the appearance of an unexpected prolonged PR interval followed by a shorter PR interval. The recognition of this manifestation at the sinoatrial junction is suggested when, during regular sinus rhythm with manifest episodes of Mobitz type II sinoatrial block, the sinus rhythm is at times also complicated by a sudden unexpected prolongation of a P-P interval, which is followed by an shortened P-P interval. This new phenomenon is termed by Mobitz type II delay.

Electrocardiography↗
PubMed1988

"Irregular" ventricular parasystole: the influence of sinus rhythm on a parasystolic focus.

Fifteen cases of ventricular parasystole were analyzed to determine whether the interectopic intervals were regular, as expressed by long intervals being exact multiples of the short ones, or not. The regularity of the interectopic intervals was assessed by means of the variation index: the ratio of the maximal difference between various measurements of the parasystolic cycle length and the mean parasystolic cycle length. Three out of 15 cases had a variation index less than 5, and were classified as "regular parasystole." Twelve cases were associated with a variation index greater than 7.5, and were classified as "irregular parasystole." The cases of irregular parasystole were then analyzed to determine whether the variability of the interectopic intervals was casual or dependent on action of the sinus beats. A parasystolic resetting by critically timed sinus impulses (a form of intermittent parasystole) was evident in three cases. The irregularity in the remaining nine cases was due to modulation (viz., due to electrotonic influence exerted by the sinus beats on the parasystolic focus). In every case of modulated parasystole a phase-response curve was constructed, which enabled an analysis of all the interectopic intervals on the basis of a time-dependent effect exerted by the sinus impulses on an otherwise rhythmic parasystolic focus.

Adolescent↗
PubMed1988

Concealed ventricular bigeminy with exceptions due to time-dependent modulation of an ectopic rhythm.

This presentation reflects a case of atypical concealed bigeminy, where some interectopic intervals contain even numbers of sinus beats. Exceptions to the rule of concealed bigeminy only occur during slowing of the sinus node. The pattern is explained on the basis of modulated parasystole, by drawing a phase-response curve which explains all the interectopic intervals on the basis of the modulating effect exerted by the sinus impulses upon a parasystolic focus.

Aged↗
PubMed1987

Non-sustained ventricular tachycardia with Wenckebach exit block.

A case of non-sustained, recurrent ventricular tachycardia, manifesting with irregular R-R intervals, is described. Analysis of a long electrocardiographic recording reveals that the arrhythmia is generated by a regularly discharging ectopic ventricular focus, the R-R interval variations being due to a Wenckebach form of exit block.

Adult↗
PubMed1987

Concealed ventricular quadrigeminy linked to atrial quadrigeminy: a manifestation of modulated parasystole.

Analysis of a long electrocardiographic recording including many atrial and ventricular extrasystoles shows that when atrial extrasystoles are in a quadrigeminal distribution, the ventricular extrasystoles also manifest a quadrigeminal distribution or reflect a distributional pattern of concealed quadrigeminy. Conversely, when atrial extrasystoles are other than in a quadrigeminal distribution, the ventricular extrasystoles do not occur in a quadrigeminal or concealed quadrigeminal distribution. This pattern is explained on the basis of modulated parasystole. A biphasic phase-response curve explains the observed phenomena on the basis of variations of the parasystolic cycle length due to the modulating effect of supraventricular beats.

Aged↗
PubMed1987

Changes in morphology of the paced QRS complex related to atrial contraction.

A patient with 2:1 AV block underwent temporary ventricular pacing. All the paced stimuli resulted in ventricular capture, but a marked variability in morphology of the paced QRS complexes occurred. Two different types of paced QRS complex (labeled A and B) were recognized. Type B complexes were manifest only when the pacing stimulus was preceded by a sinus P wave within a time interval ranging from 0.15 to 0.52 sec. The P wave-induced changes in morphology of the paced QRS complexes were interpreted as due to displacement of the pacing ventricular lead caused by atrial systole.

Aged↗