Role of echocardiographic dyssynchrony parameters in predicting response to cardiac resynchronization therapy.

AIMS: In the present study, we compare different echocardiographic cardiac dyssynchrony parameters, both of intraventricular and interventricular dyssynchrony, in order to predict response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: In a population of 77 heart failure patients scheduled for CRT, we measured the interventricular mechanical delay (IVMD) and we analyzed six different parameters of intraventricular dyssynchony: the tissue Doppler imaging (TDI) septum-lateral wall delay, the systolic dyssynchrony index; the three-dimensional SD of the time to reach minimum systolic volume for 16 left ventricular segments (3D-SDI); the speckle-tracking radial, circumferential and longitudinal dyssynchrony. At 6 months of follow-up, 61 (79%) patients were responders (≤15% in left ventricular end-systolic volume). On baseline analysis, 3D-SDI, radial strain, longitudinal strain and circumferential strain and IVMD were significantly higher in responder group (10.8 ±â€Š3.9 vs. 7.6 ±â€Š1.8% for 3D-SDI; P = 0.003; 212 ±â€Š91 vs. 125 ±â€Š36 ms for radial strain, P = 0.0003; 185 ±â€Š83 vs. 134 ±â€Š53 ms for longitudinal strain, P = 0.02; 190 ±â€Š80 vs. 130 ±â€Š54 ms for circumferential strain, P = 0.006; 45 ±â€Š21 vs. 30 ±â€Š20 ms for IVMD; P = 0.01). On univariate and multivariate analysis, only IVMD was significantly associated with a complete echocardiographic response to CRT. 3D-SDI and radial strain present the better values of sensitivity and specificity, overall if associated to an evaluation of IVMD (sensitivity 76%, specificity 88%, for 3D-SDI + IVMD; sensitivity 80% and specificity 85% for radial strain + IVMD). CONCLUSION: The novel parameters, such as 3D-SDI and speckle-tracking (particularly radial strain), offer better diagnostic accuracy in identifying patients who are responders to CRT. The addition of the contemporary parameter of IVMD improves the diagnostic accuracy.

Efficacy of low interatrial septum and right atrial appendage pacing for prevention of permanent atrial fibrillation in patients with sinus node disease: results from the electrophysiology-guided pacing site selection (EPASS) study.

BACKGROUND: The role of pacing sites and atrial electrophysiology on the progression of atrial fibrillation (AF) to the permanent form in patients with sinus node dysfunction (SND) has never been investigated. The aim of the study was to investigate the relationship between atrial electrophysiology and the efficacy of atrial pacing at the low interatrial septum (IAS) or at the right atrial appendage (RAA) to prevent persistent/permanent AF in patients with SND. METHODS AND RESULTS: The Electrophysiology-Guided Pacing Site Selection (EPASS) Study was a prospective, controlled, randomized study. Atrial refractoriness, basal and incremental conduction times from the RAA to the coronary sinus ostium were measured before implantation, and the difference (ΔCTos) was calculated. Patients with ΔCTos ≥ 50 ms (study group) and those with ΔCTos <50 ms (control group) were randomly assigned to RAA or IAS with algorithms for continuous atrial stimulation "on." The primary end point was time to development of permanent or persistent AF within a 2-year follow-up in the study group, IAS versus RAA. Data were analyzed by intention to treat. One hundred two patients (77 ± 7 years, 44 mol/L) were enrolled, 69 (68%) in the study group and 33 (32%) in the control group. Of these, 97 ended the study, respectively, randomly assigned: 29 IAS versus 36 RAA and 18 IAS versus 14 RAA. After a mean follow-up of 15 ± 7 (median, 17) months, 11 (16.6%) patients in the study group met the primary end point: 2 IAS versus 9 RAA (log rank=3.93, P=0.047). CONCLUSIONS: In patients with SND and intra-atrial conduction delay, low IAS pacing was superior to RAA pacing in preventing progression to persistent or permanent AF. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239226.

Transthoracic second harmonic two- and three-dimensional echocardiography for detection of patent foramen ovale.

AIMS: Transoesophageal echocardiography (TEE) with contrast administration is still considered as the reference method for the detection of patent foramen ovale (PFO) with interatrial shunt, but it is a semi-invasive exam. The aim of the present study is to evaluate a role of two- and three-dimensional transthoracic echocardiography (TTE and R3DTE) as a diagnostic alternative to transcranial Doppler ultrasound (TCD) and TEE for detection of atrial right-to-left shunt. METHODS AND RESULTS: Seventy-five patients with history of cerebrovascular events were subjected to four diagnostic examinations: TCD, TTE, R3DTE, and TEE, with bubble contrast. Bubbles in the left atrium within three cardiac cycles were considered diagnostic for PFO and later as a pulmonary shunt. Greater than 20 bubbles in the left atrium were considered a large shunt and <20 a small shunt. Every exam was read blinded to the results of the others. From the 75 enrolled patients, 62 (82.6%) patients showed right-to-left shunt with TEE; the results were also positive in 53 patients using TCD (70.6%), in 53 using R3DTE (70.6%), and in 55 using TTE (73.3%) (P = NS). There is a statistically significant superiority for TEE in the capacity of detecting shunts compared with TCD (P < 0.024), TTE (P < 0.018), and R3DTE (P < 0.018). The TEE presents a superior ability to recognize mild/moderate interatrial shunts respect to other exams (P = 0.003), without differences for shunts of high degree. In comparison to the TEE, the sensitivity is 89% for TTE, 88% for R3DTE, and 85% for TCD; the specificity is 100% for TTE and R3DTE, and 90% for TCD; the positive predictive value is 100% for TTE and R3DTE, and 98% for TCD; and the negative predictive value is 65% for TTE, 65% for R3DTE, and 53% for TCD. Considering only for mild/moderate shunts, the diagnostic accuracy is clearly inferior (sensitivity 63% for TTE, 58% for R3DTE, and 53% for TCD). CONCLUSION: In this cohort of patients, TEE confirms the role of 'gold standard' exam for the detection of PFO; the non-invasive methods, and the TTE in particular, present a good diagnostic accuracy, but are inferior to the TEE because of the low negative predictive value and the non-optimal detection of small shunts. If the only purpose of TEE is the detection of significative interatrial shunt, TEE can be replaced by TTE. The R3DTE presents a good diagnostic accuracy, provides a better anatomical definition of the interatrial septum, and may have a role in this setting of patients, but does not add a lot to the TTE for the diagnosis.

Atypical arrhythmic complications in familial hypokalemic periodic paralysis.

Familial hypokalemic periodic paralysis is an autosomal dominant muscle disorder characterized by episodic attacks of muscle weakness, accompanied by a decrease in blood potassium levels. It is based on genetic mutations in the genes CACNA1S (most frequent, encoding the skeletal muscle calcium channel) and SCN4A (10% of cases, encoding the sodium channel). Few cases have been reported with cardiac dysrhythmia. We report a rare case of a patient with a novel SCN4A mutation who presented, on ECG, extreme bradycardia and syncopal sinus arrest that required a temporary pacemaker implant

Digitalis must be banished from the table: a rare case of acute accidental Digitalis intoxication of a whole family.

Advanced Digitalis intoxication is a rare event, mainly associated with overdose in patients with Digitalis therapy. We report an unusual case of acute 'familiar' digitalis poisoning in three patients who had eaten potato dumplings flavoured with leaves of Borago officinalis L. unconsciously mixed with leaves of Digitalis purpurea L. A complicated clinical course with marked bradyarrhythmias was presented, with good evolution thanks to the use of digoxin-specific antibody Fab fragments. The theme of the domestic use of plants with medicinal effects has been treated and discussed.

Diagnosis of paroxysmal atrial fibrillation in patients with implanted pacemakers: relationship to symptoms and other variables.

BACKGROUND: Atrial fibrillation (AF) is not always accompanied by clear-cut symptoms and symptoms suggestive of AF may not correspond to a genuine AF episode. The study prospectively evaluated the burden of asymptomatic AF episodes in pacemaker patients (for sick sinus syndrome) with a history of documented paroxysmal AF. METHODS: Consecutive patients were enrolled and implanted with dual-chamber pacemakers equipped with diagnostic features for AF monitoring. Each patient was instructed about typical AF symptoms and was asked to keep a detailed log of symptoms. Stored pacemaker data were analyzed using only AF episodes >30 s. RESULTS: The mean follow-up was 16 +/- 6 months and 102 patients were enrolled (73 +/- 7 years, 59 M). Thirteen patients (13%) dropped out with the development of permanent AF and their data were discarded. Twenty-three patients (26%) without device-stored AF episodes all reported at least one annotated AF episode. There were 1,245 device-stored AF episodes in 66 (74%) out of 89 patients. Patients reported 1,141 episodes of AF-related symptoms. Only 240 (21%) corresponded to a genuine device-stored AF event. The sensitivity and positive predictive value of symptoms to detect AF were respectively 19% and 21%. Episode duration, rate increase at the onset of the arrhythmia, heart disease, or antiarrhythmic drug therapy showed no statistically significant differences comparing symptomatic and asymptomatic episodes. CONCLUSIONS: Many pacemaker patients with paroxysmal AF can develop AF-like symptoms in the absence of device-stored AF. AF-related symptoms have low sensitivity and low positive predictive value in patients with permanent pacemakers.

Biventricular pacemaker lead thrombosis: a rare case treated with surgical thrombectomy.

Right cardiac thrombosis is an infrequent complication after pacemaker implant. We report a patient who received a biventricular implantable cardioverter defibrillator, with a large mobile thrombus, adherent to the left ventricular lead. This catheter was partially dislocated, with a large, mobile loop through the right atrium and right ventricle; so the lead thrombus could alternately obstruct the pulmonary valve and the tricuspid valve. We believe that this is the first case of left ventricular lead thrombosis, in which the surgical treatment included thrombectomy with conservation of the catheter that was anchored to the internal right atrial wall in order to limit its great motility, maintaining the contribution to the cardiac resynchronization.

[Pulmonary embolism associated with paradoxical arterial embolism in a patient with patent foramen ovale]. / Embolia polmonare associata ad embolia arteriosa paradossa in paziente con pervietà del forame ovale.

Paradoxical embolism and patent foramen ovale have represented an issue of great interest during the last years, because of the strong correlation with cryptogenic stroke in young patients. The coexistence of pulmonary and paradoxical embolism is even more rare. We present the case of a patient with evidence of concomitant pulmonary embolism and paradoxical systemic arterial embolism, which suggests the presence of patent foramen ovale. The available literature about this infrequent clinical event is also reviewed.

[Effects of pretreatment with amiodarone infusion in patients with persistent atrial fibrillation submitted to external electrical cardioversion: a single center experience]. / Effetti del pretrattamento con infusione di amiodarone in pazienti affetti da fibrillazione atriale persistente, sottoposti a cardioversione elettrica esterna: esperienza di un singolo centro.

BACKGROUND: Several studies demonstrated the efficacy of amiodarone pretreatment in achieving bet-ter outcomes after electrical cardioversion of atrial fibrillation. In the majority of cases, oral amiodarone for at least 1 month was administered, with the result of lengthening of pre-cardioversion time. Only one study in the literature reported high-dose amiodarone infusion, showing an increase in the incidence of slow arrhythmias. The aim of this study was to test the efficacy of pretreatment infusion of a single dose of amiodarone few hours before electrical cardioversion in restoring sinus rhythm and reducing the incidence of early arrhythmic recurrences. METHODS: The study was retrospective. We analyzed a population of 155 patients with persistent atrial fibrillation, from May 2003 to November 2005. The first group of 86 patients was treated with amiodarone at the dose of 4 mg/kg in 30 min, few hours before electrical cardioversion; the second group of 69 patients was treated with electrical cardioversion without pharmacological pretreatment. The two groups were homogeneous for age, sex, coronary artery disease, duration of arrhythmia, atrial dimensions, left ventricular ejection fraction, and paddle position for electrical cardioversion. RESULTS: There were no significant differences between the two groups in terms of efficacy of cardioversion (95.3 vs 91.3%, p = NS). Pretreatment with bolus of amiodarone significantly reduced the incidence of immediate recurrence (3.5 vs 17.4%, p < 0.05) and the mix of immediate and early recurrence (19.7 vs 33.3%, p < 0.05). There were no significant differences in the incidence of late recurrences (17.4 vs 13%, p = NS). There were no significant bradyarrhythmias in the two groups. Amiodarone pretreatment did not reduce energy delivery to obtain cardioversion. CONCLUSIONS: Amiodarone pretreatment with intravenous bolus few hours before electrical cardioversion reduces short-term recurrences of atrial fibrillation. It does not reduce energy delivery of electrical cardioversion and does not increase the incidence of slow arrhythmias. Randomized prospective studies are warranted to confirm these findings.

Interventricular cardiac resynchronization with right ventricular apical pacing in a patient with Ebstein's defect.

We present the case of a patient with Ebstein's defect surgically corrected, and a complete right bundle branch block (RBBB) documented on echocardiogram. After an episode of near syncope due to a high-grade atrioventricular (AV) block, the patient was assisted with a bicameral DDDR pacemaker implanted with traditional right ventricular apical pacing. After the DDDR, and after stimulation with an AV delay of 180 ms, a narrow QRS complex was observed. Meanwhile, the typical left bundle branch block morphology of the right ventricular pacing and the native RBBB morphology were missing. The QRS complex narrowing persisted, even with physical activity and also with the heart rate progression. An echocardiographic study confirmed an improvement of the cardiac resynchronization parameters with this programmed stimulation.

Left ventricular pseudoaneurysm: an atypical case associated with a small ventricular septal defect.

We present an atypical case of postinfarction left ventricular pseudoaneurysm involving the posterobasal septal wall, with protrusion into the right ventricle, associated with a small septal defect and left-to-right shunt. In this case, a conservative approach was adopted rather than surgical management, and the patient had a good clinical outcome. Subsequent evaluation with two-dimensional colour Doppler, three-dimensional echocardiography and 16-slice computed tomography is reported.

[Severe bradycardia in an asymptomatic young subject: is there an indication to permanent cardiac pacing?]. / Bradicardia estrema in un giovane soggetto asintomatico: indicazione all'elettrostimolazione permanente?

Bradycardic effects of severe weight loss are well known like those observed in anorexia nervosa resulting from an increase in vagal tone associated with a low calorie-protein diet. We here report the case of a 19-year-old patient with asymptomatic severe bradycardia, which developed after voluntary weight loss of more than 30 kg during a few months. In absence of symptoms, ventricular arrhythmia or structural heart disease, and owing to normal ventricular function, no permanent pacemaker implantation was undertaken. After a follow-up of more than 15 years, clinical conditions are stable, the patient is asymptomatic and bradycardic, and no changes in weight are reported.

[Late pacemaker pocket erosion: epidemiologic analysis in a region of North-Western Italy (Piedmont and Valle d'Aosta)]. / Il decubito tardivo della tasca pacemaker o defibrillatore impiantabile: indagine epidemiologica di tre anni in piemonte-valle d'Aosta.

BACKGROUND: Pacemaker pocket erosion is still a relevant clinical problem as it may be the cause of septicemias and/or endocarditis with consequent poor prognosis. The true incidence of this complication is rather variable in the various series of cases reported in the literature ranging between 0.9 and 5% when early infective complications are included. METHODS: In order to evaluate the real incidence of this complication we performed a retrospective analysis on the data coming from all the pacemaker implanting centers in Piedmont. Data collection forms were completed for each patient presenting this kind of complication from 1996 through 1998; the follow-up lasted for at least 36 months. RESULTS: In the 21 centers (81% of all implanting centers in Piedmont) in which completed data were collected, 7793 pacemaker and 289 automatic cardioverter-defibrillator (ICD) implants were performed. During the follow-up 100 cases of pacemaker pocket erosion were observed with a total incidence of 1.28% (range 0-3.1%); no cases of ICD pocket erosion were reported. Diabete mellitus was the most frequent associated disease (25% of patients), about 30% of patients were taking antiplatelet drugs. The kind of surgical procedure performed to resolve the problem was different in the various centers according to personal experience and to the various evaluations performed by each physician. CONCLUSIONS: Our study demonstrates that the overall incidence of late pacemaker pocket erosion in our region is absolutely acceptable even in spite of relevant differences in the various implanting centers. A system of continuous monitoring with the data collection of all the performed procedures would be extremely useful to constantly check the quality level both locally and regionally.