Early detection of cancer therapy cardiotoxicity by radionuclide angiography: An update.

Cancer therapy-induced cardiotoxicity is an emerging clinical and healthcare issue. Myocardial dysfunction and heart failure are mostly responsible for increased cardiovascular mortality in cancer disease survivors. Several imaging surveillance techniques have been proposed for early diagnosis of cancer therapy-induced cardiac dysfunction. Our aim was to provide an update of radionuclide angiography applications in this field. Radionuclide angiography is widely used to assess left ventricular ejection fraction (LVEF) throughout cancer treatment, especially in patients with limited acoustic window. Additional prognostic data may be provided by phase analysis and diastolic function evaluation. Low LVEF and high approximate entropy at baseline seem to be predictors for cancer therapy-induced cardiac dysfunction. A decrease in peak filling rate and/or an increase in time to peak filling rate may be observed in patients undergoing anthracycline and/or trastuzumab administration. Diastolic function impairment may precede or not LVEF decrease. In conclusion, recent studies have provided novel insights into the possible role of radionuclide angiography in the early detection of cancer therapy cardiotoxicity. While interpreting the results of a radionuclide angiography examination, an integrated approach combining the evaluation of LVEF, LV diastolic function, and phase analysis may be useful to improve risk stratification of cancer patients treated with cardiotoxic agents.

Pocket histology at cardiac implantable electronic device replacement: What's new?

BACKGROUND: Repeated procedures involving the cardiac implantable electronic device (CIED) pocket increase the infection risk, and the extent of pocket adhesions may prolong the procedure time. Few data on pocket histology at the time of CIED replacement are available. OBJECTIVE: The purpose of this study was to describe CIED pocket histology in a cohort of patients undergoing CIED replacement or upgrade. METHODS: All consecutive patients undergoing CIED replacement or upgrade at our center between November 2019 and May 2020 were enrolled. Subclinical pocket infection was ruled out by physical inspection and laboratory parameters before the procedure. Pocket tissue specimens from the anterior and posterior pockets were obtained intraoperatively. A systematic histological analysis of capsular thickness, fibrous connective tissue, neovascularization, inflammation, and calcifications was performed. RESULTS: Thirty patients (6 women, 20%) were enrolled. The mean capsular thickness was 0.8 ± 0.3 mm in the anterior wall and 1.1 ± 0.4 mm in the posterior wall. Subcapsular fibrosis was mild and multifocal in the anterior wall and moderate and focal in the posterior wall. Neovascularization was focal in most cases, and vessel remodeling mainly involved the tunica media. Chronic inflammation was usually mild and nongranulomatous, and in a quarter of cases, subacute exudative fibrous inflammation was detected in the posterior pocket wall. CONCLUSION: The CIED pocket is a histopathologically dynamic environment, given the coexistence of both a subacute foreign body response and fibrous tissue growth, implying continuous remodeling due to an injury-repair mechanism. Strategies to interact with foreign body response might minimize inflammatory pocket activity, especially device encapsulation by tight fibrous tissue, and possibly complications related to repeated CIED procedures.

Axillary vein access for antiarrhythmic cardiac device implantation: a literature review.

The current narrative review provides an update of available knowledge on venous access techniques for cardiac implantable electronic device implantation, with a focus on axillary vein puncture. Lower procedure-related and lead-related complications have been reported with extrathoracic vein puncture techniques compared with intrathoracic accesses. In particular, extrathoracic lead access through the axillary vein seems to be associated with lower complication incidence than subclavian vein puncture and higher success rate than cephalic vein cutdown. In literature, many techniques have been described for axillary vein access. The use of contrast venography-guided puncture has facilitated the diffusion of the axillary vein approach for device implantation. Venography may be particularly useful in specific demographic and clinical device implantation contexts. Ultrasound-guided or microwire-guided vascular access for lead positioning can be considered a valid alternative to venography, although current applications for axillary vein puncture need further evaluations.

Asymptomatic lone atrial fibrillation - how can we detect the arrhythmia?

Atrial fibrillation (AF) may occur in the absence of identifiable causes, co-morbidities or structural cardiac disease (lone AF). Silent AF is common and patients may have a completely asymptomatic arrhythmia or may experience both symptomatic and asymptomatic AF episodes. It has been estimated that among patients with recognized AF, one third has no appreciable symptoms. In contemporary clinical practice, AF remains largely underdiagnosed and 25% of patients with AF-associated cardioembolic stroke have not been previously diagnosed with AF. The strategies for AF screening include opportunistic and systematic screening. Several methods for AF detection are nowadays available: from very simple (pulse palpation) to more advanced technologies proposed for ambulatory external monitoring of variable time duration. In patients previously implanted with cardiac electrical devices with an atrial lead, according to current clinical indications, the ability to continuously detect AF and to monitor its evolution is magnified, and AF burden can be precisely measured and monitored along with time. Similar information on AF burden can be also obtained by implantation of subcutaneous cardiac monitors that rely on the analysis of consecutive RR intervals for the diagnosis of AF. The prognosis is generally favorable for patients presenting with lone AF, but adverse outcomes, including stroke and thromboembolic events may occur at long term, in association with aging, or the development of underlying heart disease, or progression from paroxysmal to permanent AF. In this respect, the role of new technologies and diagnostic tools for AF detection and monitoring should be fully defined.

Role of drugs and devices in patients at risk of sudden cardiac death.

The search for effective treatment for preventing sudden cardiac death (SCD) initially started with anti-arrhythmic agents in high-risk patients, but the use of randomized controlled trials clearly led to the conclusion that an approach based on anti-arrhythmic agents is not useful, and sometimes potentially harmful (the risk of arrhythmic death was increased up to 159% in CAST study). Today the approach to SCD prevention includes considering both the setting of patients who have already presented a cardiac arrest or a malignant ventricular tachyarrhythmias (secondary prevention of SCD) and the much broader setting of primary prevention in patients at variable degrees of identifiable risk. For secondary prevention of SCD, implantable cardioverter defibrillation is now the standard of care (the risk of overall mortality may be reduced by 20-31%), and anti-arrhythmic agents, specifically amiodarone, have only a complementary role (for reducing device activations or for preventing atrial fibrillation). For primary prevention of SCD in high-risk patients, cardioverter defibrillators have nowadays specific indications in patients with left ventricular dysfunction (often in combination with cardiac resynchronization therapy), where the risk of overall mortality may be reduced by 23-54%. For the large number of subjects who have some risk of SCD, but are not identified as at high risk of SCD, a series of drugs could exert a favorable effect (beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blocker agents, statins, omega-3 fatty acids and aldosterone antagonists), and for some of them evidence is emerging, from subgroup analysis, of possible SCD prevention capabilities.

Long-term follow-up of patients with syncope evaluated by head-up tilt test.

BACKGROUND: Clinicians may be tempted to consider a positive head-up tilt test (HUTT) an unfavorable prognostic indicator. We investigated whether results of routine HUTT predict long-term recurrence of syncope. METHODS: We analyzed syncope recurrence at long-term among 107 patients (mean age 51 +/- 20 years) receiving HUTT for diagnostic evaluation of unexplained/suspected neurocardiogenic syncope in our Institute. RESULTS: HUTT was positive in 76 patients (vasodepressive response, n = 58; cardioinhibitory, n = 5; mixed, n = 13). During a median follow-up of 113 months (range, 7-161), 34 (32%) patients experienced recurrence (24 [32%] with positive HUTT during 110 months (7-159); 10 [32%] with negative HUTT during 120 [22-161] months). Actuarial freedom from recurrence at 10 years did not significantly differ for patients with positive/negative test results (after passive/active phases) or with different positive response patterns (vasodepressive, cardioinhibitory, mixed). By contrast, history of >4 syncopes in the 12 months preceding HUTT stratified risk of recurrence, irrespective of HUTT positivity/negativity. At Cox proportional hazards analysis, history of >4 syncopes in the 12 months preceding HUTT was the single independent risk factor for recurrence both in the overall study population (HR, 1.7; 95% CI, 1.07-2.69) and within the subset of patients who tested positive (HR, 1.83; 95% CI, 1.07-3.17). CONCLUSIONS: This long-term follow-up study reinforces the concept that a positive HUTT should not be considered an unfavorable prognostic indicator; frequency of recent occurrences may be a more valid predictor.

Phrenic stimulation: a challenge for cardiac resynchronization therapy.

BACKGROUND: Phrenic stimulation (PS) may hinder left ventricular (LV) pacing. We prospectively observed its prevalence in consecutive patients with cardiac resynchronization therapy (CRT) devices. METHODS AND RESULTS: In the years 2003 to 2006, 197 patients received a CRT device. PS and LV threshold measurements were carried out at implantation and at 6-month follow-up. LV reverse remodeling was assessed by echocardiography before implantation and at follow-up. LV lead placement was lateral/posterolateral in 86% of patients. Both PS and LV reverse remodeling occurred most frequently at the lateral/posterolateral LV pacing sites (P<0.001). PS was detected in 73 (37%) of patients and was clinically relevant in 41 (22%). The detection of PS at implantation had a poor sensitivity, as it occurred only in left lateral or sitting position in 27 patients. Ten patients (5%) underwent repeated surgery and 4 (2%) had their CRT turned off because of PS. At follow-up, we could manage PS noninvasively in 32 patients with a small PS-LV threshold difference: in 20 by cathode programmability (3 also thanks to automatic management of LV output) and in 12 (without cathode programmability) by programming the LV output as threshold +1 V. CONCLUSIONS: PS may seriously hinder CRT. A bipolar LV lead and cathode programmability are mandatory to avoid PS by changing the LV pacing vector at target sites for CRT. LV stability at target sites despite PS should also be pursued by these means. The automatic adjustment of LV pacing output is complementary in patients with a small PS-LV threshold difference.

Outcome of cardioverter-defibrillator implant in patients with arrhythmogenic right ventricular cardiomyopathy.

The aim of the present study was to investigate outcomes of implantable cardioverter-defibrillator (ICD) treatment in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). We reviewed baseline/follow-up data of 15 consecutive ARVC patients (mean age 55 +/- 15 years) and 30 randomly drawn patients with coronary artery disease (CAD) (mean age 60 +/- 10 years) with matching durations of follow-up (all implanted with ICDs for primary/secondary prevention of sudden death). At implant, appropriate placement of the RV lead was more difficult in ARVC patients. During follow-up (median 41 months), appropriate interventions for any ventricular tachyarrhythmias occurred in 8 (53%) ARVC patients and 17 (57%) CAD patients, but the occurrence of high rate (>240 beats/min) ventricular tachyarrhythmias was higher in ARVC patients. Inappropriate ICD interventions occurred in 5 (33%) ARVC patients and 10 (33%) CAD patients. Lead-related adverse events requiring surgical revision occurred in 7 (47%) ARVC patients as compared with 4 (13%) CAD patients (P = 0.0004). While ICD implantation is highly effective for prevention of sudden death in ARVC, it does carry elevated burdens of long-term lead-related adverse events. These findings underline the need of careful follow-up in ARVC aimed at early recognition of complications that can impair ICD function.