The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study

OBJECTIVE

Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations.

OBJECTIVE

We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa-NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa.

METHODS

We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30-70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa-NTG and FFR were measured.

RESULTS

283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa-NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa-NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84-0.92, P < 0.001) and 0.94 (95% CI: 0.92-0.96, P < 0.001) respectively. The optimal cutoff values of resting baseline Pd/Pa and Pd/Pa-NTG for an FFR > 0.80, were >0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa-NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa-NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis.

CONCLUSION

The cutoff value of acute Pd/Pa-NTG > 0.88 has a high NPV meaning adenosine-FFR can be avoided in almost half of lesions.

[Impotence and cardiovascular disease: a new perspective in the health-care compromise of the urologist]

OBJECTIVES

To review the evidence currently available to establish the pathogenic connection between erectile dysfunction (ED) and cardiovascular disease (CVD), and the effects this scientific progress has introduced in the classical impotence urology clinic.

METHODS

We reviewed the most recent publications about this disease (2000-2004) and the concept of endothelial dysfunction by appropriate MEDLINE searches, with specific selection of reviews and clinical practice guidelines.

RESULTS

The fact that ED and CVD share risk factors is confirmed; the pathogenic unity of both processes having endothelial dysfunction as the underlying problem; anticipation of ED over CVD in time of presentation; notable increase of research about this issue over the last two years; the change of scenario in the impotence urology clinics due to these findings.

CONCLUSIONS

The number of cases in which ED is not an organ disease but an early symptom of endothelial dysfunction forces changes in the extent and depth of the diagnostic, prognostic and follow-up strategies in the urology impotence clinics of extraordinary importance from both the individual and health-care politics point of view.

Ventricular arrhythmias: mechanisms and actions of antiarrhythmic drugs

Choosing the correct drug therapy of ventricular arrhythmias is difficult, even when, for discussion, reentry is arbitrarily considered the mechanism for arrhythmias. To counter ventricular arrhythmia with its many possible reentry circuits, an antiarrhythmic drug should lengthen the refractory period but not affect conduction velocity. Antiarrhythmic drugs for ventricular rhythm disturbances do work by prolonging the refractory period, slowing conduction, or both. However, in anatomically and functionally determined circuits, drugs may stop or decelerate tachycardia; but in some cases antiarrhythmics, particularly class I drugs, can theoretically accelerate tachycardia. Individual drug level determinations are important; what is therapeutic in one patient may worsen the arrhythmia in another. The changeable electrophysiologic milieu in early stages of ischemic heart disease makes controlled investigations difficult. However, individual variance calls for further systematic investigation of new ways to interrupt, isolate, or destroy the reentry pathway, and such investigation probably should be conducted in patients with inducible ventricular tachycardia.

Retrorectal cyst-hamartomas. Report of two cases with adenocarcinoma developing in one

The clinical and pathological features of two cases of retrorectal cyst-hamartoma are presented. Both lesions were characterized by the presence of cysts lined by mucus-producing, ciliated and transitional epithelium. The anatomical and histological findings in our cases of retrorectal cyst-hamartoma are in favor of an embryologic origin from remnants of the postanal gut. The differential diagnosis includes teratomas, dermoid cysts, duplication cysts of the rectum, anal gland cysts, and anal gland carcinomas. To avoid complications, particularly malignant transformation, early complete excision is recommended.

Inter- and intraatrial dissociation during spontaneous atrial flutter: evidence for a focal origin of the arrhythmia

Programmed electrical stimulation of the heart was performed in 2 patients with spontaneous atrial flutter. Patient 1 was a young man with paroxysmal atrial flutter that had proved resistant to drug therapy and who was studied during an episode of sustained flutter. In this patient rapid atrial pacing from the coronary sinus at a critical rate faster than the intrinsic flutter rate provoked local atrial fibrillation in the mid and low right atrium which persisted after termination of pacing. In spite of persistent local fibrillation in these regions, atrial flutter continued in the left atrium and the high right atrium. A second burst of pacing resulted in restoration of sinus rhythm. Patient 2 was an elderly woman with probable sick sinus syndrome who developed spontaneous atrial flutter during the course of an electrophysiologic investigation. During flutter intracavitary recordings from multiple sites in the atria revealed a pattern of 3:2 Wenckebach conduction between the left atrium and the high right atrium, with block of every third atrial depolarization at the latter site. These results indicate that atrial flutter may exist at some sites in the atria which are functionally dissociated from the remainder of the atrial tissue, thus supporting the hypothesis that flutter in some patients may be focal in origin.

Termination of circus movement tachycardia utilizing an accessory atrioventricular pathway by retrograde concealed penetration of the atrioventricular node through the bundle branch system. A mechanism of tachycardia termination in Wolff-Parkinson-White syndrome

A 30 year old woman with Wolff-Parkinson-White syndrome underwent electrophysiologic study for investigation of circus movement tachycardia utilizing the accessory pathway for retrograde conduction. The accessory pathway was located on the right side. Episodes of circus movement tachycardia with left and right bundle branch block were induced. Some episodes of circus movement tachycardia with left bundle branch block terminated spontaneously. Two episodes of spontaneous termination at the level of the atrioventricular (A-V) node were preceded by prolongation of the H-V interval causing delay in atrial activation. This delayed atrial cycle was then followed paradoxically by spontaneous termination of the tachycardia in the A-V node. A similar phenomenon could be demonstrated reproducibly with single echo beats induced by coronary sinus extrastimuli. It appears that retrograde concealed penetration of the A-V node through the bundle branch system during anterograde left bundle branch block is the most likely mechanism for this phenomenon.

Spontaneous termination of circus movement tachycardia using an atrioventricular accessory pathway: incidence, site of block and mechanisms

The incidence, mechanisms and sites of block of spontaneous termination of circus movement tachycardia (CMT) using an atrioventricular accessory pathway (AP) were analyzed in 24 consecutive patients (17 with Wolff-Parkinson-White syndrome and seven with a concealed AP) who were not receiving antiarrhythmic drugs. Spontaneous termination of tachycardia occurred in 10 patients (105 episodes). A reduced "safety margin" of tachycardia was the only factor that was significantly more common in the patients who manifested spontaneous termination (p less than 0.01). The site of spontaneous block was located in the AP in six patients (50 episodes), atrioventricular node (AVN) in six patients (37 episodes) and His-Purkinje system (HPS) in three patients (18 episodes). At least 14 mechanisms leading to block in the tachycardia circuit were identified. Labile conduction during tachycardia occurred at multiple sites (AVN, His bundle, bundle branches, and AP). Analysis of the duration of tachycardia before spontaneous termination showed a characteristic time pattern for block at each site, consistent with the autonomic and electrophysiologic changes that occur after induction of tachycardia. Spontaneous termination of CMT using an AP is a common phenomenon. Many mechanisms are involved, which are often complex and dependent on interplay of the electrophysiologic characteristics of the components of the tachycardia circuit.

Comprehensive clinical electrophysiologic studies in the investigation of documented or suspected tachycardias. Time, staff, problems and costs

To assess time, staff, problems and costs involved in clinical electrophysiologic studies for documented or suspected tachycardia, 33 consecutive cases were analyzed prospectively. At least seven staff members were used for each study. Insertion of catheters required 24--105 minutes (mean 63 +/- 20 minutes). Programmed stimulation required 12--210 minutes (mean 87 +/- 38 minutes). Total fluoroscopy times were 6--67 minutes (mean 22 +/- 15 minutes). Each study used 360--2100 feet (mean 1260 +/- 390 feet) of recording paper. Detailed analysis of tracing took 1--11 hours (mean 5 +/- 2.5 hours). Delays occurred during electrophysiologic study in 25 cases (76%), with multiple causes of delay in 14 cases (42%). These were caused by 1) difficulty in obtaining venous access (five patients); 2) difficult initial catheter placement (15 cases); 3) repositioning of catheters during stimulation (17 cases); 4) sustained atrial fibrillation (four cases). Coronary sinus catheterization was achieved from the groin in 21 of 27 cases (78%) in whom a sustained attempt was made. The approximate cost of each study was greater than $800. Our data show that clinical electrophysiologic studies in the investigation and management of tachycardia are difficult, time-consuming and expensive.