Sustained beneficial hemodynamic effects of low transdermal nitroglycerin doses compared with placebo in patients with congestive heart failure.

In an attempt to resolve some of the controversies concerning the dose requirements and duration of effects of transdermal nitroglycerin (NTG) in patients with heart failure (CHF), the short-term hemodynamic responses to transdermal NTG, in a 20 cm2 self-adhesive patch (10 mg/24 h), were evaluated in 10 patients with severe chronic CHF using a randomized, within-patient, double-blind, placebo-controlled cross-over trial. Serial hemodynamic measurements over 24 h revealed sustained effects that began 1 h after the application of nitroglycerin patch and fully persisted throughout the study. The peak effect occurred at 4 h with the pulmonary capillary wedge pressure decreasing from 33.7 +/- 8.4 to 21.4 +/- 9 mmHg (mean +/- SD) (p less than 0.05) and the cardiac index increasing from 2.5 +/- 0.6 to 3 +/- 0.6 l/min/m2 (p less than 0.01). Transdermal nitroglycerin also significantly reduced pulmonary arterial and right atrial pressures (from 43.5 +/- 9.5 to 31 +/- 11.4 and from 7.4 +/- 6.6 to 3.8 +/- 4.7 at peak effect, respectively) as well as pulmonary and systemic vascular resistances (from 10.7 +/- 6.6 to 6.5 +/- 3.2 and from 26.2 +/- 5.1 to 22.5 +/- 5.7, respectively). There was no change in heart rate or systemic arterial pressure. These beneficial hemodynamic responses persisted for 24 h. No rebound deterioration occurred upon withdrawal of the nitroglycerin. No significant hemodynamic changes occurred during placebo treatment period. Thus, low doses (10 mg/24 h) of transdermal nitroglycerin induce significant hemodynamic benefit that is sustained for 24 h in patients with heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Termination of ventricular tachycardia by noninvasive methods]. / Interruzione di una tachicardia ventricolare con metodiche non invasive.

Present paper reports on a patient referred for sustained, hemodynamically well tolerated, ventricular tachycardia, terminated by noninvasive temporary pacing. The tachycardia was refractory to chest tump and intravenous standard drugs (lidocaine and propafenone). Demonstration of spontaneous atrioventricular dissociation and ventricular capture during transesophageal atrial pacing allowed rapid and correct diagnosis. Overdrive with external noninvasive ventricular pacing proved effective in terminating ventricular tachycardia and converting it to sinus rhythm. These observations suggest that noninvasive approach to hemodynamically stable ventricular tachycardia can provide a safe and effective alternative to more aggressive medical management.

[Myocardial revascularization may resolve arrhythmic warm-up in patients with implantable cardioverter-defibrillator: 2 case reports]. / La rivascolarizzazione miocardica come risoluzione del riscaldamento aritmico in pazienti con cardiovertitotre-defibrillatore impiantabile: due casi clinici]

Patients with ventricular arrhythmias and coronary artery disease may have a poor clinical outcome because of an increased risk of sudden cardiac death. In these patients therapeutic approaches include two main strategies: automatic implantable cardioverter-defibrillator (ICD) and antiarrhythmic drugs (when left ventricular function is preserved). Patients with arrhythmic warm-up sustained by ischemic attacks may be stabilized after percutaneous or surgical revascularization. We report the cases of 2 ICD patients, in whom the correction of myocardial ischemia was successful in preventing further ICD discharges. In the first patient with known coronary artery disease (previous acute myocardial infarction and left ventricular ejection fraction 30%) a sudden arrhythmic warm-up was reported with 70 ICD discharges in 24 hours; the patient underwent coronary artery bypass surgery and only few isolated episodes of ventricular tachycardia were observed during the following 34 months. In the second patient with a history of dorsal acute myocardial infarction and two previous interventions of coronary artery bypass graft surgery, we observed a sudden and unexpected arrhythmic instabilization with several ICD discharges. After percutaneous transluminal angioplasty of a graft stenosis, the clinical situation was stabilized and no more ICD activations were observed during the follow-up. In selected patients arrhythmic warm-up can rely on an ischemic substrate, then a careful re-evaluation for ischemia is mandatory in order to resolve the situation.

[Single-lead VDD pacing with sensing dipole in the coronary sinus: a case of implantation through persistent left superior vena cava]. / Stimolazione VDD monocatetere con sensing in seno coronarico: un caso di impianto attraverso vena cava superiore sinistra persistente.

We report the case of a VDD single-lead pacemaker implantation through a persistent left superior vena cava in a 48-year-old male patient with recurrent episodes of syncope due to paroxysmal atrioventricular block. VDD lead insertion through the anomalous venous structure led to positioning of the floating sensing dipole into the coronary sinus, in a very large and stable sensed atrial signal due to the close anatomic relationship between the coronary sinus and the left atrium. Shortness of the sensed atrioventricular interval allowed VDD stimulation to occur only in the case of paroxysmal atrioventricular block.

[The functional and hemodynamic benefits of automatic atrioventricular interval delay in permanent atrial synchronized pacing]. / Benefici funzionali ed emodinamici dell'accorciamento automatico dell'intervallo atrio-ventricolare nella stimolazione cardiaca permanente di tipo atrio-sincronizzato.

OBJECTIVES: In order to assess possible functional and hemodynamic benefits of different programming of atrioventricular (AV) delay--156 ms fixed vs 156 to 63 adaptive--two maximal exercise tests (cyclette) were performed in 8 patients (6 males, 2 females; 69 +/- 6 years) implanted with Chorus 6003 (Ela Medical, France) DDD pacemakers for complete AV block with normal sinus node function. METHODS: The measured parameters were: pacing rate, cardiac output (thermodilution method), oxygen consumption (2001 gas-exchange analyser), arterial-venous difference (derived from pulmonary oxygen saturation, through an optical-fibers Swan-Ganz catheter coupled to an Oximetric3-Abbott oximeter), human atrial natriuretic factor and lactate plasmatic levels, anaerobic threshold. RESULTS: A better cardiac output (11.4 +/- 1.7 vs 10.1 +/- 1.8 l/min) and oxygen consumption (1521 +/- 425 vs 1408 +/- 465 ml/min) were observed at maximal exercise with adaptive rather than with fixed AV delay programming (p < 0.05); moreover anaerobic threshold point was reached later during exercise test with adaptive AV delay (242 +/- 92 vs 216 +/- 109 sec, p = 0.05). On the contrary, with adaptive and fixed AV delay, there were not statistically different values of maximal heart rate (139 +/- 9 vs 139 +/- 9), levels at maximal exercise of arterial-venous difference (12.5 +/- 2 vs 12.8 +/- 1.4 Vol%O2), human atrial natriuretic factor (63 +/- 17 vs 78 +/- 48 pg/ml), lactate (29 +/- 15 vs 29 +/- 18 mg/dl), and oxygen consumption at anaerobic threshold point (772 +/- 164 vs 786 +/- 229 ml/min). CONCLUSIONS: In DDD pacing adaptive AV delay causes aerobic and hemodynamic benefits.

A new approach to the prevention of endless loop tachycardia in DDD and VVD pacing.

Endless loop tachycardia (ELT) is a possible complication in dual chamber pacing; it is usually prevented by programming the atrial refractory period (PVARP) longer than the retrograde ventriculoatrial (VA) conduction interval; this in some patients limits the upper rate. In 15 patients with a DDD (nine patients) or a single-pass lead VDD pacemaker (six patients) and retrograde atrial activation, telemetric recording documented a significant difference in amplitude of antegrade, and retrograde atrial potentials (VDD 1.21 +/- 0.32 mV vs 0.56 +/- 0.23 mV, P = 0.008; DDD 2.7 +/- 1 vs 1.8 +/- 1 mV, P = 0.038; Student's t-test for paired data). In 3/15 patients ELT stopped after programming of atrial sensitivity to a value greater than the retrograde P wave amplitude; in 11/15 patients this occurred at a sensing value lower than or equal to retrograde P wave amplitude with a high pass band filter operating. One patient required PVARP lengthening. Holter monitoring showed no more ELTs. In most patients with a DDD or single-pass lead VDD pacemaker with widely programmable sensing amplitude and Hi/Low bandpass filters, individual programming of atrial channel sensitivity prevents ELT without affecting the PVARP and, consequently, upper rate limit.

[An intrapatient comparison of adaptation to aerobic and anaerobic exertion during 3 types of physiological cardiac stimulation in chronotropic failure of the sinus node: DDD, VVIR and DDDR]. / Confronto intrapaziente dell'adattamento allo sforzo aerobico ed anaerobico durante tre tipi di stimolazione cardiaca fisiologica nell'insufficienza cronotropa del nodo del seno: DDD,VVIR e DDDR.

In sick sinus syndrome with chronotropic incompetence, dual-demand rate responsive pacing (DDDR) may be better than ventricular-inhibited rate responsive pacing (VVIR) and dual-demand pacing without rate responsive function (DDD). In order to compare exercise performance during different activity-driven pacing modes, 15 patients (9 males, 6 females; mean age 59 +/- 13 years), implanted with Synchrony 2020T pacemaker (Siemens-Pacesetter Inc, USA, activity sensor) for sick sinus syndrome, randomly performed 3 treadmill tests (modified Bruce protocol) during DDD, VVIR and DDDR pacing, with pacing heart rate, oxygen consumption (Q-Plex 5000, Quinton), work time, anaerobic threshold and human atrial natriuretic peptide level monitoring. Four patients were excluded from the data results (3 for normalization of chronotropic incompetence, 1 for angina pectoris during rate responsive pacing). Heart rate at the end of exercise was significantly higher during VVIR pacing mode (131 +/- 21 b/min) and DDDR (136 +/- 14 b/min) than during DDD pacing mode (105 +/- 21 b/min), p < 0.05. During DDDR we obtained a significantly higher work tolerance (652 +/- 161 s) and a higher oxygen uptake (22.7 +/- 7.1 ml/kg/min) than during DDD (565 +/- 106 s; 20.1 +/- 6.5 ml/kg/min) and VVIR (599 +/- 155 s; 18.8 +/- 6.5 ml/kg/min), p < 0.05. Also the work time and the oxygen uptake at anaerobic threshold were better during DDDR stimulation (350 +/- 119 s; 14.2 +/- 4.9 ml/kg/min) than during DDD (280 +/- 101 s; 12.2 +/- 4.6 ml/kg/min) and VVIR pacing mode (306 +/- 122 s; 11.6 +/- 4.60 ml/kg/min), p < 0.05. On the contrary, human atrial natriuretic factor values at the maximum exercise were lower during DDD (139 +/- 100 pg/ml) than VVIR (256 +/- 182 pg/ml) and DDDR (209 +/- 195 pg/ml) pacing mode, p < 0.05. In conclusion, DDDR pacing proved to be better than VVIR and DDD in patients with sick sinus disease and chronotropic incompetence.

[Arrhythmia in patients with a DDD bicameral pacemaker]. / Aritmie in pazienti portatori di pacemaker bicamerale DDD.

Dual chamber pacemakers, with coordinate atrial and ventricular sensing and stimulation (DDD), even if allowing "physiological" pacing, exhibited new and complicated arrhythmic manifestations, whose real frequency is still unascertained. In 65 patients (mean age 68 +/- 12 years), implanted with a DDD multiprogrammable device (15 pts. Medtronic Versatrax 7000 A, 50 pts. Pacesetter AFP 283), we carried out a 24 hours Holter monitoring while pacemaker was programmed with standard parameters. In a subset of 15 patients Holter monitoring was performed before and after pacemaker implantation. We evidenced: a) atrial sensing and/or pacing malfunction in 3 patients (4.5%); b) pacer-unrelated arrhythmias in 49 patients (75%): atrial extra beats 35 patients (54%), ventricular extra beats 23 patients (35%), non-sustained ventricular tachycardias 10 patients (15%), atrial tachyarrhythmias 8 patients (12%); c) supraventricular arrhythmias with PM-mediated high rate ventricular pacing in 12 patients (18%); d) PM induced and sustained endless loop tachycardias in 31 patients (47%); e) arrhythmias depending on over-sensing in 11 patients (17%): myopotential interferences 9 patients (14%), cross-talk ventricular pacing inhibition 2 patients (3%). The prevalence of ventricular arrhythmias was not different before and after the pacemaker implantation. The prevalence of atrial extrasystoles (53% versus 40%) and atrial tachyarrhythmias (26% versus 6%) decreased after the pacemaker implantation. Aimed reprogramming with progressive extension of atrial refractory period (from 250 to 400 msec and DDX) achieved disappearance of PM-endless loop tachycardias in 95%. Use of multi-programmability lowered the incidence and symptoms of most PM-related arrhythmias. Drug therapy was of choice in clinical arrhythmias unrelated to pacer.

[False left atrial mass caused by hiatal hernia: a clinical case and review of the literature]. / Falsa massa atriale sinistra causata da ernia iatale: caso clinico e revisione della letteratura.

Two-dimensional echocardiography is the technique of choice for identifying cardiac masses. Unfortunately, adjacent structures compressing the atrial wall may lead to misdiagnosis. Clinicians should promptly recognize this phenomenon and the related diagnostic features. The case of a 90-year-old woman presenting with a history of recent onset effort dyspnea is described. On transthoracic two-dimensional echocardiography a left atrial mass which closely mimicked an atrial myxoma was evident. A tomographic scan revealed a large sliding hiatus hernia, which was confirmed on traditional radiographic examination. The echocardiographic characteristics of the mass are described in detail, as well as a review of the literature for the purpose of a correct differential diagnosis.

[Physiologic limitations of dual chamber stimulators during physical activity]. / Limitazioni fisiologiche degli stimolatori bicamerali durante l'attività fisica.

Dual chamber DDD pacing is fully physiologic when chronotropic response of sinus node to exercise is normal and when retrograde ventriculo-atrial conduction is absent. Comparison of results from exercise test with increasing work load showed that atrial-triggered ventricular pacing provides a significant functional benefit (delta VO2 15%) P less than 0.01, if compared with fixed rate ventricular pacing. The benefit is closely related with the amount of sinus rate increase during exercise. In patients with sinus node syndrome the atrial triggered ventricular pacing rate did not show significant increase during exercise and exercise capability was similar to that observed with fixed ventricular pacing. Retrograde ventriculo-atrial conduction was observed in 56% of patients with sick sinus syndrome and 28% of patients with complete AV block and was the reason for endless loop tachycardias (ELTs). ELTs can be eliminated by lengthening atrial refractory period (ARP). In patients with ARP greater than or equal to 250 ms (47%), mild (8:7, 4:3) or important (2:1) AV block appeared during exercise test, with sudden drop of pacing rate and cardiac output at highest work load. Among other "physiologic" pacing modes, respiration traced ventricular stimulation showed high physiologic sensitivity (90%) and haemodynamic benefit comparable to that obtained during dual chamber pacing and without the related disadvantages.

Experiencia clínica minilap para la esterilización quirúrgica / Clinical experience minilap for surgical sterilization

El presente trabajo muestra la experiencia clínica en el HBLT con la aplicación de la técnica de Minilap en la esterilización quirúrgica femenina. Se realizó un total de 118 esterilizaciones quirúrgicas, de las cuales 108 (91,5 por ciento del total de casos) fueron bajo anestesia local. En la gran mayoría de los casos (96,3 por ciento) resultó ser un método muy bien tolerado. Se presentaron sólo 2 casos de lesión vesical (1,7 por ciento) que se resolvieron sin inconvenientes y con una evolución favorable