Adenosine-sensitive atrial reentrant tachycardia originating from the atrioventricular nodal transitional area

INTRODUCTION: Atrial tachycardia shows wide variations in its electrophysiologic properties and sites of origin. We report an atrial tachycardia with ECG manifestations and electrophysiologic characteristics similar to an atypical form of AV nodal reentrant tachycardia (AVNRT). METHODS AND RESULTS: This supraventricular tachycardia was observed in 11 patients. It was initiated by atrial extrastimulation with an inverse relationship between the coupling interval of an extrastimulus and the postextrastimulus interval. Its induction was not related to a jump in the AH interval, and its perpetuation was independent of conduction block in AV node. Ventricular pacing during tachycardia demonstrated AV dissociation without affecting the atrial cycle length. A very small dose of adenosine triphosphate (mean 3.9 +/- 1.2 mg) could terminate the tachycardia. The earliest atrial activation during tachycardia was recorded at the low anteroseptal right atrium with a different intra-atrial activation sequence from that recorded during ventricular pacing, where the tachycardia was successfully ablated in 9 of 10 attempted patients. Bidirectional AV nodal conduction remained unaffected after successful ablation. CONCLUSION: There may be an entity of adenosine-sensitive atrial tachycardia probably due to focal reentry within the AV node or its transitional tissues without involvement of the AV nodal pathways. This tachycardia can be ablated without disturbing AV nodal conduction from the right atrial septum.     

The treatment of refractory ischemic ventricular tachycardia by endoventricular patch plasty reconstruction of the left ventricle

BACKGROUND: Engagement in therapeutic activity among stroke inpatients is advocated by many rehabilitation professionals. However, there is a lack of published evidence to indicate whether this is currently being achieved. OBJECTIVE: To investigate the extent and types of 'rehabilitation' activities on a new neurological rehabilitation ward, and examine change in patients' behaviour related to the new environment and new initiatives. DESIGN: Five one-week observation periods were conducted over two years, with a total of 67 patients being observed. A comparison was made with results of an earlier study of stroke patients' activities conducted at the same hospital. RESULTS: Patients spent an average 43 min per day with therapists (9% of the working day) and this was only marginally supplemented by self-exercise (2% of the working day--approximately 10 min). However, the provision of a new rehabilitation environment was associated with a marked decrease in the time patients spent at their bedsides, and a decrease in time spent passively gazing or watching others. CONCLUSIONS: Overall there was some positive change in patients' behaviour. We suggest that structured guidance is required from the whole multidisciplinary team to stimulate more self-directed therapy practice and recreation.     

Isolated congenital diverticulum of the left ventricle disclosed by ventricular tachycardia in a 72-year-old woman

A 72-year-old woman presented with poorly tolerated ventricular tachycardia reduced by intravenous amiodarone. The possibility of an ischaemic aetiology led us to perform coronary angiography. The coronary arteries were pathological. Left ventricular angiography revealed limited anterior hypokinesia and a large contractile apical pouch appended to the left ventricle by a long narrow neck. Despite the appearance suggestive of congenital left ventricular diverticulum (contractility, narrow neck) and because of the coexistence of ischaemic heart disease, we preferred to confirm the muscular nature of the diverticulum by myocardial thallium scintigraphy, which showed reversible decreased uptake in the anterior zone related to coronary artery disease, and confirmed the muscular nature of the diverticulum which showed normal thallium uptake. MRI clearly visualized the ventricular ectasia attached by a narrow neck to the rest the left ventricle. This long narrow neck indicated that this muscular diverticulum constituted a congenital diverticulum. The contribution of ultrasonography was limited by a poorly defined point during the examination. This congenital diverticulum, discover during adulthood, and previously asymptomatic, is a rare lesion, in the light of a review of the literature.     

Successful radiofrequency ablation of idiopathic left ventricular tachycardia at a site away from the tachycardia exit

OBJECTIVES: This study sought to assess the possibility of ablating verapamil-responsive idiopathic left ventricular tachycardia at a site distant from the tachycardia exit and thus to define the tachycardia circuit. BACKGROUND: The nature of the reentry circuit in idiopathic left ventricular tachycardia is unclear. If the circuit is of considerable size, then it should be possible to ablate the tachycardia at a site distant from the exit site. METHODS: Electrophysiologic studies and radiofrequency ablation were performed in 27 consecutive patients with verapamil-responsive idiopathic left ventricular tachycardia. In all 27 patients, the tachycardia exit site was defined as the site where the earliest Purkinje potential was recorded > or = 25 ms before the onset of the QRS complex during the tachycardia and where the pace map QRS complex resembled that during the tachycardia. A potential ablation site other than the exit site was then sought around the midseptum, proximal to the exit site. At such sites the tachycardia could be terminated transiently by pressure applied to the catheter tip, without induction of ventricular ectopic beats. RESULTS: The potential ablation site, other than the tachycardia exit site, was identified in seven male patients (mean [+/-SD] age 31 +/- 12 years, range 13 to 52). Application of the radiofrequency current at this site resulted in termination of the tachycardia within 1 to 5 s (mean 2.9 +/- 1.6), and successful ablation of the tachycardia was achieved in all seven patients (success rate 100%, 95% exact confidence interval 0.5898 to 1). The mean distance between the ablation site and the tachycardia exit site was 3.1 +/- 0.7 cm (range 2.0 to 4.0). A presystolic Purkinje spike was recorded 14 +/- 5 ms (range 8 to 20) before the onset of the QRS complex during the tachycardia. During the follow-up period of 24 +/- 11 months (range 12 to 39), there was no recurrence of tachycardia in these seven patients. CONCLUSIONS: Successful ablation of idiopathic left ventricular tachycardia can be achieved at sites away from the tachycardia exit site in some patients. This finding suggests that the reentry circuit is likely to be of considerable size, encompassing the middle, inferior and lower aspects of the left interventricular septum.     

Repetitive monomorphic tachycardia from the left ventricular outflow tract: electrocardiographic patterns consistent with a left ventricular site of origin

OBJECTIVES: This study sought to characterize the electrocardiographic patterns predictive of left ventricular sites of origin of repetitive monomorphic ventricular tachycardia (RMVT). BACKGROUND: RMVT typically arises from the right ventricular outflow tract (RVOT) in patients without structural heart disease. The incidence of left ventricular sites of origin in this syndrome is unknown. METHODS: Detailed endocardial mapping of the RVOT was performed in 33 consecutive patients with RMVT during attempted radiofrequency ablation. Left ventricular mapping was also performed if pace maps obtained from the RVOT did not reproduce the configuration of the induced tachycardia. RESULTS: Pace maps identical in configuration to the induced tachycardia were obtained from the RVOT in 29 of 33 patients. Application of radiofrequency energy at sites guided by pace mapping resulted in elimination of RMVT in 24 (83%) of 29 patients. In four patients (12%), pace maps obtained from the RVOT did not match the induced tachycardia. All four patients had a QRS configuration during RMVT with precordial R wave transitions at or before lead V2. In two patients, RMVT was mapped to the mediosuperior aspect of the mitral valve annulus, near the left fibrous trigone; catheter ablation at that site was successful in both. In two patients, RMVT was mapped to the basal aspect of the superior left ventricular septum. Catheter ablation was not attempted because His bundle deflections were recorded from this site during sinus rhythm. CONCLUSIONS: RMVT can arise from the outflow tract of both the right and left ventricles. RMVTs with a precordial R wave transition at or before lead V2 are consistent with a left ventricular origin.     

Performance of the lift ventricle in left ventricular obstructive cardiomyopathy

Whether volume expansion influences NaC1 reabsorption by the diluting segment of the nephron remains a matter of controversy. In the present studies this question has been examined in normal unanesthetized dogs, undergoing maximal water diuresis. Free water clearance (CH2O/GFR) has been used as the index of NaC1 reabsorption in the diluting segment. Three expressions have been employed for "distal delivery" of NaC1: a) V/GFR, designated as the "volume term"; b) (CNa/GFR + CH2O/GFR), the "sodium term;" and c) (CC1/GFR + CH2O/GFR), the "chloride term". The validity of these terms is discussed. Three techniques were used to increase distal delivery: 1) the administration of acetazolamide to dogs in which extracellular fluid (ECF) volume was not expanded (grop 1); 2) "moderate" volume expansion (group 2); and 3) "marked" volume expansion (group 3). CH2O/GFR increased progressively with rising values for "distal delivery" regardless of which term was used to calculate the latter. With all three delivery terms, differences in distal NaC1 reabsorption emerged between the two volume-expanded groups, though only with the "chloride" term did substantial differences also emerge between the nonexpanded group 1 dogs and both volume-expanded groups. In group 1, values for CH2O/GFR increased in close to a linear fashion up to distal delivery values equal to 24% of the volume of glomerular filtrate. However, at high rates of distal delivery the rate of rise of CH2O/GFR was less in group 2 than in group 1 and the depression of values was even greater in group 3. Within the limits of the techniques used, the data suggest that volume expansion inhibits fractional NaC1 reabsorption in the diluting segment of the nephron in a dose-related fashion. The "chloride" term was found to be superior to the "volume" and "sodium" terms in revealing these changes.     

Pseudoaneurysm of the left ventricle following repair for ventricular septal perforation

The patient was a 64-year-old man who was treated surgically for an infarct-related ventricular septal perforation. Pseudoaneurysm of the left ventricle was recognized on the 38th postoperative day. Emergency surgery was performed. It seemed that insufficient resection of the infarcted myocardium was performed during the initial surgery to avoid narrowing the ventricular dimension by direct closure of the left ventricle, but this resulted in pseudoaneurysm of the left ventricle. Left ventricular free wall plasty with a patch should be performed during the initial surgery.     

A reconstruction of the left ventricle for post infarction left ventricular aneurysm complicated by ventricular septal perforation--a case report

The aging of bitemarks through the subjective interpretation of visual signs has created an area of controversy in the forensic science community. The healing dynamics of these bite wounds has been insufficiently studied and is poorly understood. A review of the literature related to bitemark aging was undertaken in an effort to summarize the currently published information on this misunderstood subject.     

Can indices of left ventricular function be applied to the right ventricle?

This article compares conventional indices of contractile function in the right and left ventricles. The low operating pressures and left ventricles. The low operating pressures and complex geometry complicate evaluation of right ventricular function. However, when the characteristics of its vascular load are taken into account, the complex right ventricular chamber has pump properties that are similar to the high pressure left ventricular chamber.     

Reversibility of "tachycardia induced cardiomyopathy" following the cure of idiopathic left ventricular tachycardia using radiofrequency energy

We report a case of incessant ventricular tachycardia with right bundle branch block and left axis deviation morphology resulting in severe LV dysfunction and congestive heart failure. Radiofrequency ablation of the appropriate site in the region of posteroapical part of the LV septum resulted in the cure of the arrhythmia. On a 3-month follow-up, the LV size and function returned to normal.     

Acute alterations in systolic ventricular interdependence-mechanical dependence of right ventricle on left ventricle following acute alteration of right ventricular free wall

The purpose of the study was to examine whether systolic ventricular interdependence can be acutely altered by changes in the mechanical properties of the ventricular wall. In eight acute canine studies, we released an aortic constriction during diastole. We measured right ventricular (RV) pressure changes (dPr) caused by sudden changes in left ventricular (LV) pressure (dPl). Measurements were obtained during control, 10 min after right coronary artery occlusion, and then 15 min after injecting glutaraldehyde into the RV free wall. By superimposing the pressure tracings of the beats immediately before and after the aortic release, the instantaneous pressure difference ratio (dPr/dPl) was calculated during systole. Maximal value of the pressure difference ratio decreased from control 0.11 +/- 0.04 to ischemia 0.08 +/- 0.03; (p < 0.05) and increased with glutaraldehyde 0.15 +/- 0.06; (p < 0.05). Thus, acute ischemia in RV free wall decreased the magnitude of systolic ventricular interdependence from LV to RV, while glutaraldehyde, which stiffens the RV free wall, increased the magnitude.     

Apical muscular ventricular septal defects between the left ventricle and the right ventricular infundibulum. Diagnostic and interventional considerations

BACKGROUND: Effective transcatheter or surgical closure of apical muscular ventricular septal defects (VSDs) requires accurate delineation of variable and often complex anatomy. These defects have generally been considered as communications between the apexes of both left and right ventricles. METHODS AND RESULTS: Among 50 consecutive patients with multiple muscular VSDs referred for transcatheter device closure between October 1987 and April 1993, a subset of 10 patients (aged 7 days to 28 years) with apical muscular VSDs shared a unique set of anatomic characteristics: (1) large and often single opening in the left ventricle; (2) multiple right ventricular openings in the anterior aspect of the apical septum; and (3) separation of the right ventricular apical region into which the VSDs open from the rest of the right ventricular inflow and outflow by prominent muscle bundles. Additional analysis of the anatomy by use of echocardiography and cineangiography showed that these muscular defects were between the left ventricular apex and right ventricular infundibular apex. In 6 patients, the transcatheter devices used to create a septum in these hearts were placed in the right ventricle, straddling muscle bundles that separated the apical VSD from the rest of the right ventricular inflow and outflow, resulting in incorporation of a portion of the right ventricular infundibular apex into the physiological left ventricle. Three patients had devices placed between the apexes of the left ventricle and the infundibulum. The defect closed spontaneously within the right ventricle in 1 patient. One patient died after surgery for tetralogy of Fallot in situs inversus. The remaining 9 patients were all clinically well at the time of their most recent follow-up visit (follow-up duration, 32 +/- 11 months). This distinct type of apical VSD was identified by echocardiography in 20 of 274 patients who were followed up clinically for muscular VSDs. CONCLUSIONS: Left ventricular-infundibular apical VSDs constitute a distinct morphological type of muscular VSD that can be distinguished by echocardiography and cineangiography. In selected cases, the infundibular apex can be separated from the rest of the right ventricular inflow and outflow to eliminate flow across these defects.     

Correlation between ventricular arrhythmia and geometric remodeling of the left ventricle in arterial hypertension

Sensitization to contact allergens in atopics was assessed by grouping 989 patients, who were routinely patch tested, by their personal atopic status. Sensitization to > or = 1 allergens occurred in 38% of the 191 patients with existing atopic eczema, in 53% of the 120 with a past history of atopic eczema, in 54% of the 156 with only mucous membrane atopy and in 50% of the 510 who were not atopic. Sensitization to perfume, a common environmental allergen, was similar in all 4 groups, as was nickel among women. Patients with atopic eczema should be patch tested.     

Catheter ablation for ventricular tachycardia from a diverticulum at the right ventricular outflow tract

A case is presented of a 73-year-old man with drug resistant ventricular tachycardia that originated from the right ventricular outflow tract. A right ventriculogram showed a diverticulum in the interventricular septum at the right ventricular outflow tract. Low energy radiofrequency catheter ablation within the diverticulum was performed successfully and safely.     

Initiating sequences in exercise induced idiopathic ventricular tachycardia of left bundle branch-like morphology

The human gene set was originally identified as a component of the set-can fusion gene produced by a somatic translocation event in a case of acute undifferentiated leukemia. In the developing kidney, set was highly expressed in the zone of nephron morphogenesis. Recently, SET was shown to be a potent and specific inhibitor of protein phosphatase 2A, a family of major serine/threonine phosphatases involved in regulating cell proliferation and differentiation. The current study sought to define further the role of SET in the regulation of renal cell proliferation and tumorigenesis. The mRNA encoding SET was expressed at much higher levels in transformed human and rodent cell lines than in cultured renal epithelial and primary endothelial cells. Consistent with a role for SET in cell proliferation, set mRNA expression was markedly reduced in cells rendered quiescent by serum starvation, contact inhibition, or differentiation. Previous findings during renal development were extended by demonstrating that SET protein expression is also much greater in developing rat and human kidney than in fully differentiated, mature kidney. Finally, high levels of set mRNA and SET protein expression were found in Wilms' tumor, but not in renal cell carcinoma, adult polycystic kidney disease or in transitional cell carcinoma.     

Doppler stress echocardiography of the left and right ventricle: a new echo device to quantify left ventricular backward failure

OBJECTIVES: A novel non-invasive procedure which evaluates left-right ventricular interaction is introduced. This procedure is suitable for the classification of congestive heart failure. METHODS: In 48 patients showing mild, moderate or advanced stage congestive heart failure (NYHA I-III) Doppler echocardiography was performed at rest, during and after submaximal bicycle exercise. Mitral (m) and tricuspid (t) filling parameters were determined: early diastolic (VEm, VEt) and atrial maximal velocities (VAm, VAt), the velocity integrals (Em, Et, Am, At) and the corresponding ratios (VE/VAm, VE/VAt, E/Am, E/At). Group 1 (n = 29) was composed of those patients presenting with a VE/VAm < 1 at rest. Four individuals (group 2) were found to have a VE/VAm ratio < 1 during exercise only. Six other patients showing a dilated left ventricle or an ejection fraction of less than 40% produced false negative results in left ventricular Doppler examination (VE/VAm > 1) at rest and during exercise (group 3). In 9 cases (group 4) systolic function, size and Doppler echocardiographic parameters of the left ventricle were proven to be normal. RESULTS: The VE/VAt-ratio decreased notably during exercise (p < 0.05) but increased again after exercise in group 3. In the groups 1 and 2 similar changes occurred as well, however not to a significant degree. In group 4, exercise VE/VAt ratio did not differ from values seen at rest or during recovery (variability 4%). CONCLUSION: The results of this study indicate, that high sensitivity towards left ventricular backward failure can be achieved for Doppler stress echocardiography by extending the examination to right-sided diastolic parameters.     

Disopyramide in ventricular tachycardia

A procedure for the measurement of free erythrocyte protoporphyrin (FEP) in a drop of blood collected on filter paper is described. The method is useful as a screening test for lead poisoning in children. Based on the FEP finding and blood lead tests, asymptomatic children are classified into four major categories. A course of action is suggested for each category.     

Unusual features of right and left idiopathic ventricular tachycardia abolished by radiofrequency catheter ablation

Two unusual cases are presented with idiopathic right and left ventricular tachycardia (IVT) with intriguing clinical and electrophysiological characteristics. The first patient with a sustained IVT of right ventricular outflow tract origin, and an electrophysiological mechanism suggesting reentry, had been resuscitated from cardiac arrest. The second patient had an IVT with a left bundle branch block morphology, which originated from the basal-septal region of the left ventricle (left ventricular outflow tract tachycardia). Both patients were cured with radiofrequency catheter ablation, guided by endocardial activation sequence and pace mapping.     

Verapamil-sensitive left anterior fascicular ventricular tachycardia: results of radiofrequency ablation in six patients

INTRODUCTION: Verapamil-sensitive left ventricular tachycardia (VT) with a right bundle branch block (RBBB) configuration and left-axis deviation has been demonstrated to arise from the left posterior fascicle, and can be cured by catheter ablation guided by Purkinje potentials. Verapamil-sensitive VT with an RBBB configuration and right-axis deviation is rare, and may originate in the left anterior fascicle. METHODS AND RESULTS: Six patients (five men and one woman, mean age 54+/-15 years) with a history of sustained VT with an RBBB configuration and right-axis deviation underwent electrophysiologic study and radiofrequency (RF) ablation. VT was slowed and terminated by intravenous administration of verapamil in all six patients. Left ventricular endocardial mapping during VT identified the earliest ventricular activation in the anterolateral wall of the left ventricle in all patients. RF current delivered to this site suppressed the VT in three patients (ablation at the VT exit). The fused Purkinje potential was recorded at that site, and preceded the QRS complex by 35, 30, and 20 msec, with pace mapping showing an optimal match between the paced rhythm and the clinical VT. In the remaining three patients, RF catheter ablation at the site of the earliest ventricular activation was unsuccessful. In these three patients, Purkinje potential was recorded in the diastolic phase during VT at the mid-anterior left ventricular septum. The Purkinje potential preceded the QRS during VT by 66, 56, and 63 msec, and catheter ablation at these sites was successful (ablation at the zone of slow conduction). During 19 to 46 months of follow-up (mean 32+/-9 months), one patient in the group of ablation at the VT exit had sustained VT with a left bundle branch block configuration and an inferior axis, and one patient in the group of ablation at the zone of slow conduction experienced typical idiopathic VT with an RBBB configuration and left-axis deviation. CONCLUSION: Verapamil-sensitive VT with an RBBB configuration and right-axis deviation originates close to the anterior fascicle. RF catheter ablation can be performed successfully from the VT exit site or the zone of slow conduction where the Purkinje potential was recorded in the diastolic phase.