External Scaffold for Venous Graft to Treat Chronic Limb-Threatening Ischemia: Results of the FRAME Vascular Support

Background: The surgical treatment of chronic limb-threatening ischemia and optimal conduit choice are extensively debated. The presence of suboptimal autologous material, such as varicosities or venous aneurysms, might impair long-term outcomes. Therefore, kink-resistant external supports have been advocated in the recent literature to improve the conduit quality and outcomes. This study analyzes the FRAME external support in venous ectasic grafts in patients with chronic limb-threatening ischemia. Methods: From September 2017 to September 2023, a total of sixteen patients underwent CLTI surgery with FRAME external support for venous grafts. The inclusion criteria for FRAME applications were varicose or ectasic autologous material with a diameter ≥ 4.5 and ≤ 8 mm in an isolated segment or in the entire vein and a higher risk of bypass extrinsic compression (e.g., extra-anatomical venous bypass course). Results: Technical success and intraoperative patency were achieved in all cases. At 30 days, the limb salvage and survival rates were 100%. The primary bypass patency was 93.7% due to an early graft occlusion. No graft infection was registered. In one case, dehiscence of the surgical wound was treated by surgical debridement and antibiotic therapy. Minor amputation was required in four patients. Over a median follow-up of 32 months, two occlusions were observed; one was treated with reoperation and the other with major amputation. The primary patency was 68.7% and the assisted primary patency was 75%. Limb salvage rates observed during the entire follow-up period were 87.5%. No graft infections or dilatation of the reinforced veins were registered. Conclusions: For patients with CLTI undergoing infrainguinal bypass, satisfactory results in terms of patency and limb salvage rates were achieved using the autologous venous material, even if ectasic or varicose, with the vascular external support FRAME.

Chronic graft thrombosis after en bloc resection of inferior vena cava leiomyosarcoma. A case report

Leiomyosarcoma (LMS) is a rare malignant tumor originating from smooth muscle cells. Primary leiomyosarcomas arising from vessels' walls are extremely rare (2%), with LMS of inferior vena cava being the most frequent subtype. We present the case of a 45-year-old man with a past medical history of resected leiomyosarcoma of the right calf, presenting with a follow-up CT showing a retroperitoneal mass arising from the inferior vena cava, which proved to be IVC leiomyosarcoma at histopathology. The patient underwent surgical resection of the mass with prosthetic reconstruction of the IVC. Three days after surgery he developed complete thrombosis of IVC graft which persisted at 3-months follow-up imaging and was treated with pharmacological therapy. Although there are many references reporting the association between LMS of the inferior vena cava and postoperative deep vein thrombosis, to our knowledge there are no reports currently available regarding complete thrombosis of IVC vascular graft after surgical resection of IVC LMS.

P223 THYROTOXIC DILATED CARDIOMYOPATHY

Hyperthyroidism can strongly impact cardiac function. Thyrotoxicosis enhances myocardiocytes metabolism and it can be responsible for hyperdynamic circulation state leading to heart failure with preserved ejection fraction, but also left ventricle dilatation and severe contractile function impairment. It can furthermore provoke arrhythmias, mostly atrial fibrillation, but, as we are going to discuss in this case, even ventricular arrhythmias. A 40–year–old woman came to our emergency department for chest pain. ECG showed reduced R waves voltage in precordial leads and troponin I values were normal. The echocardiogram showed severe left ventricle disfunction with global hypokinesia (EF 35%) and enlarged left ventricle (LVEDD 65 mm). Blood tests revealed severe hyperthyroidism with extremely low level of TSH, FT3 13,45 pg/ml, FT4 3,4 ng/ml and thyroid echography documented multiple solid nodular formations with hypo–isoechogenic signal. She underwent a coronary angiography that showed patent coronary arteries, and a cardiac magnetic resonance confirming severe contractile impairment and hypertrabeculation of the apex and lateral wall. On the assumption of a dilated cardiomyopathy secondary to hyperthyroidism, we started treatment with methimazole, ACE inhibitors and propranolol. During hospitalization, continuous ECG monitoring recorded several episodes of non–sustained ventricular tachycardia, the longest lasting 22 seconds, so the patient was discharged with a wearable cardioverter–defibrillator. It did not record any arrhythmias and it was dismissed a month later. After almost two months of therapy, the echocardiogram showed mild left ventricular contractility improvement (EF 45%), and blood tests documented partial reduction of hyperthyroidism. A 24–hour ECG Holter did not record any arrhythmias and the patient remained asymptomatic during all the period after discharge. Even if rare, scientific literature confirms that dilated cardiomyopathy with reduced ejection fraction can occur as a complication of hyperthyroidism. After the exclusion of an ischemic cause, we underline the need for adequate initiation of treatments for thyrotoxicosis and heart failure, in order to improve chance of left ventricular function recovery. In the case discussed, after two months of therapy, EF was still not completely restored but improved from 35% to 45%, and concurrently arrhythmic risk did clearly decrease.

P376 INTRACAVITARY ABLATION OF PARASYMPATHETIC ATRIAL GANGLIONATED PLEXUS, A NEW APPROACH FOR SINUS BRADYCARDIA IN YOUNG PATIENTS

Sinus bradycardia might be a severe clinical problem, if symptomatic pacemaker implantation is needed. In younger patients this will lead to several battery changes, higher infectious risk and psychological issues. When sinus bradycardia seems related to vagal hypertone, intracavitary ablation of atrial ganglionated plexus has recently been proposed as an alternative to pacemaker implantation in symptomatic younger patients. A 44–year–old patient was admitted to the emergency department for lipothymia and fatigue. The ECG showed marked sinus bradycardia with a heart rate of 35 bpm and continuous ECG monitoring revealed episodes of Mobitz I second degree AV block and 2:1 AV block. The transthoracic echocardiography was normal. In order to reduce the effect of vagal hypertone on the heart, catheter ablation of parasympathetic atrial ganglionated plexus was performed. In the right atrium the electrophysiological study showed fragmented potentials near caval vein openings and coronary sinus osthium, while in the left atrium these were found in the posterior wall close to the pulmonary veins and near the left part of coronary sinus. Catheter stimulation of these zones determined asystolic pauses and induction of atrial fibrillation with spontaneous resolution. Catheter radio–frequency ablation was performed, at the end of the procedure increase of heart rate at 70 bpm was observed and atrial fibrillation was no more inducible during pacing. Atrioventricular Wenckebach point recorded before the procedure was 730 ms and it passed to 430 ms. At continuous ECG monitoring the heart rate remained higher than 65 bpm all over the hospitalization, without any other meaningful arrhythmias. Ablation of parasympathetic atrial ganglionated plexus is still an experimental technique but it is proving to be very interesting and promising. In the case we described the patient took a real advantage from the procedure that was measurable both with the improve of heart rate and reduction of Wenckebach point. During the procedure we associated the site of fragmented potentials with the position of each plexus; stimulation of these sites evocated a strong vagal response, confirming that fragmented potentials can be used to localize the plexus. Some authors affirmed that ablation only on right atrium might be sufficient; however, we preferred to ablate in both atria in order to make the procedure more effective. More studies are needed to identify the correct site.

QT dispersion and early arrhythmic risk during acute myocardial infarction

BACKGROUND

QT dispersion (maximal minus minimal QT interval calculated on a standard 12-lead electrocardiogram) has been suggested to reflect regional variations of ventricular repolarization and to provide a substrate for reentry ventricular arrhythmias. In this study we evaluate QT dispersion in patients with acute myocardial infarction and assess its relation with early severe ventricular arrhythmias.

METHODS AND RESULTS

We studied 101 patients with acute myocardial infarction and a control group of 97 healthy subjects. We determined QT and QTc dispersion on the electrocardiograms performed 12 hours and 3 and 10 days after the onset of symptoms in myocardial infarction patients and on the control group. The average values of QT and QTc dispersion (measured hereafter in milliseconds, ms) were as follows: 70.5 +/- 42.5-87 +/- 46.6 (after 12 hours), 66.5 +/- 37.8-76.9 +/- 43.5 (on day 3), 68.9 +/- 42-76.3 +/- 43.8 (on day 10) and 44 +/- 13.4-54.2 +/- 16.3 (in control group). We observed statistically significant differences in QT and QTc dispersion between the electrocardiogram of normal subjects and each of the three electrocardiograms performed on patients with infarction (p < 0.0005, p < 0.005). We recorded a greater QT dispersion in patients with anterior infarction with respect to those with inferior/lateral infarction (79 +/- 38.6 vs 65.2 +/- 43.16, p < 0.05) and in patients with ejection fraction < 45% (93.1 +/- 28.4 vs 68.3 +/- 34.1 p < 0.005). During the first three days, QT dispersion did not differ in patients treated with thrombolytic agents with respect to those who were untreated, while on day 10 untreated patients showed higher values (74.9 +/- 45.3 vs 60.5 +/- 37.7, p < 0.05). Creatine kinase peak level, sex and age of the patients did not influence QT dispersion. Thirteen patients (12.8%) developed severe ventricular arrhythmias within 72 hours after infarction: 8 patients (7.9%) had ventricular fibrillation and 5 patients (4.9%) had sustained ventricular tachycardia. We found higher early QT and QTc dispersion values in patients who developed severe ventricular arrhythmias (108.8 +/- 63.2 and 125.8 +/- 68.5) with respect to patients who did not (63.3 +/- 32.9 and 80.8 +/- 38.9, p < 0.0005, p < 0.0005).

CONCLUSIONS

Our data suggest that QT dispersion: 1) increases during acute myocardial infarction; 2) peaks in the early hours after symptom onset; 3) drops late after infarction in patients treated with thrombolytic agents; 4) is associated with early severe ventricular arrhythmias.

[The role of an electropharmacological transesophageal test in the prevention of paroxysmal atrial fibrillation. Experience with flecainide]

BACKGROUND

The management of patients with paroxysmal atrial fibrillation (AF) is unsuccessful, because AF recurs in about 50% of patients despite an antiarrhythmic treatment. Usefulness of non-pharmacological strategies is available in a limited subset of patients and it does not present a global solution to the problem. At present, treatment with antiarrhythmic agents is the only available tool in patients with AF recurrence. The aim of this study was to assess the predictive value of the electropharmacological transesophageal (TE) test in the management of patients with paroxysmal AF treated by flecainide.

METHODS

In 32 patients, ranging in age from 38 to 70 years (mean: 59 +/- 12 years), with documented episodes of paroxysmal AF (mean: 5.6 +/- 3.7 episodes/last year), we performed an electrophysiological transesophageal (TE) test following pharmacological wash-out. An aggressive protocol was used: step A: 10 sec atrial burst at Wenckebach point + 10 bpm, 200 and 250 bpm; step B: 10 sec atrial bursts at 300, 400, 500 and 600 bpm; step C: 8 sec increasing rate burst from 200 to 800 bpm. Induction of sustained AF (> 1 min) was considered the end-point. Patients were treated with flecainide 100 mg bid and a second TE test was performed at the steady-state, with an identical induction protocol and end-point. Based on the response of the second test, patients were divided into responders (R Group: non-inducible AF) and non-responders (NR Group: inducible, sustained AF). Patients were followed-up by periodical controls and contacted by telephone to confirm their clinical status.

RESULTS

Sustained AF was induced in 30 patients (94%) at the first TE study. Eight of them dropped-out at the time of the second TE test (6 patients for lack of consent, 1 patient for side-effects and another one for proarrhythmic effects). In the mean follow-up of 15 +/- 6 months, among patients who underwent a second TE test, AF recurrence was documented in 2 out of 14 patients from the R Group and in 7 out of 10 patients from the NR Group (p < 0.01). There were 4 AF episodes in the R Group and 19 in the NR Group (p < 0.001). We did not find significant statistical differences between the two groups in terms of age, sex, body weight, AF episodes/past year, P-wave duration, left atrial dimension, structural heart disease, AF duration at the first TE test and follow-up duration. In five patients from the NR Group with induced AF lasting > 5 min, the percentage of recurrence was 100% and there were 16 AF episodes. Global percentage of patients with recurrence was 37%.

CONCLUSIONS

Flecainide is effective in reducing the incidence of AF and results are similar to other antiarrhythmic agents generally used. The electropharmacological TE test might be a useful tool to predict the response to an antiarrhythmic treatment.

[Idiopathic atrial fibrillation of recent onset and atrial stunning: the echocardiographic evidence after pharmacological cardioversion]

Successful cardioversion of atrial fibrillation may result in prolonged recovery of normal atrial mechanical function. This prolonged recovery of atrial contraction (so-called atrial stunning) might depend on: the amount of energy delivered during direct current cardioversion; the time course between the onset of atrial fibrillation and the conversion to sinus rhythm; the size of the left atrium; the underlying cardiac disease. The aim of this study was to evaluate, in subjects with normal atrial size and without heart disease, the phenomenon of atrial stunning soon after pharmacological cardioversion of an episode of atrial fibrillation of recent onset. Twenty-five patients with an acute episode of atrial fibrillation, without evidence of heart disease and M-mode left atrial dimension (< or = 40 mm received i.v. propafenone or flecainide 2 mg/kg/10 min in order to restore sinus rhythm. Atrial fibrillation lasted < 48 hours in all patients. Doppler echocardiography was used to assess atrial function, by recording the peak velocity of atrial contraction (A wave). An echocardiographic study was performed within 12 hours of successful cardioversion and was repeated on day 3, 12 and 30. The size of the left atrium (37 +/- 3.9; 37.57 +/- 2.9; 37.4 +/- 4; 37.82 +/- 3.7 mm) and peak E velocity (57.97 +/- 18.3; 59.4 +/- 18.3; 59.0 +/- 16; 59.07 +/- 16.7 cm/s) did not show any significant differences over the time, as demonstrated by the serial echocardiographic evaluations. In contrast, both peak A velocity (cm/s) and E/A ratio evaluated within 12 hours of cardioversion (60.29 +/- 12.3 and 1.0 +/- 0.37) and on day 3 (73.71 +/- 10.7 and 0.82 +/- 0.27) were statistically different (p < 0.000001 and p < 0.00001). No further statistically significant increase was found in subsequent examinations (respectively 76.31 +/- 12 and 0.78 +/- 0.24 on day 12, and 76.91 +/- 14.8 and 0.78 +/- 0.21 on day 30). In conclusion, this study suggests that patients with alone atrial fibrillation of recent onset have a delayed recovery of normal atrial systolic function even after pharmacological cardioversion.

[Validity of some electrocardiographic criteria in left ventricular hypertrophy]

The aim of the study was the assessment of the sensitivity, specificity and accuracy of some ECG criteria of left ventricular hypertrophy (LVH). Left ventricular mass (LVM) measured on the M-mode echogram of the left ventricle was the reference standard. Ninety-four (94) unselected, consecutive clinical patients (34 women, 60 men, average age 47 years) underwent in the same day, ECG and echocardiogram. Exclusion criteria were the presence of ischemic heart disease, atrial fibrillation and Wolff-Parkinson-White syndrome. The ECG tracings were interpreted independently by 2 investigators following 5 independent criteria of LVH: 1) Sokolow-Lyon voltage criterion (SL); 2) a modified Romhilt-Estes point score (REM); 3) left atrial abnormality (LAA); 4) left ventricular strain; 5) a new voltage criterion RaVL + SV3 corrected by sex and age. The left ventricular M-mode echograms were recorded using a left parasternal approach and were interpreted independently by 2 investigators. LVM was measured using the "Penn convention" and taking the R wave peak as end-diastole. The prevalence of LVH (= LVM 215 g) in the study population was 47%. The following results were achieved (sensitivity, specificity, accuracy): SL: 68.2%, 84%, 76.6%; REM: 63.6%, 90%, 77.7%: LAA: 36.4%, 84%, 61.7%; strain 52.3%, 72%, 62.8%; RaVL + SV3: 54.5%, 82%, 69.1%. Our data suggest: 1) the high sensitivity, specificity and accuracy of Romhilt-Estes point score are confirmed; 2) the sensitivity of Sokolow-Lyon voltage criterion is reevaluated; 3) the most sensitive morphological criterion seems to be the left ventricular strain; 4) a new voltage criterion could be useful.