Marek Jastrzębski

Transvenous phrenic nerve stimulation for the treatment of central sleep apnoea in heart failure

AIMS Periodic breathing with central sleep apnoea (CSA) is common in heart failure patients and is associated with poor quality of life and increased risk of morbidity and mortality. We conducted a prospective, non-randomized, acute study to determine the feasibility of using unilateral transvenous phrenic nerve stimulation for the treatment of CSA in heart failure patients. METHODS AND RESULTS Thirty-one patients from six centres underwent attempted transvenous lead placement. Of these, 16 qualified to undergo two successive nights of polysomnography-one night with and one night without phrenic nerve stimulation. Comparisons were made between the two nights using the following indices: apnoea-hypopnoea index (AHI), central apnoea index (CAI), obstructive apnoea index (OAI), hypopnoea index, arousal index, and 4% oxygen desaturation index (ODI4%). Patients underwent phrenic nerve stimulation from either the right brachiocephalic vein (n = 8) or the left brachiocephalic or pericardiophrenic vein (n = 8). Therapy period was (mean ± SD) 251 ± 71 min. Stimulation resulted in significant improvement in the AHI [median (inter-quartile range); 45 (39-59) vs. 23 (12-27) events/h, P = 0.002], CAI [27 (11-38) vs. 1 (0-5) events/h, P≤ 0.001], arousal index [32 (20-42) vs. 12 (9-27) events/h, P = 0.001], and ODI4% [31 (22-36) vs. 14 (7-20) events/h, P = 0.002]. No significant changes occurred in the OAI or hypopnoea index. Two adverse events occurred (lead thrombus and episode of ventricular tachycardia), though neither was directly related to phrenic nerve stimulation therapy. CONCLUSION Unilateral transvenous phrenic nerve stimulation significantly reduces episodes of CSA and restores a more natural breathing pattern in patients with heart failure. This approach may represent a novel therapy for CSA and warrants further study.

Ischemic J wave: Novel risk marker for ventricular fibrillation?

C P w n i e e c H m o c n t d t c r r f e a a l s w s g c n o m l p s b a p The presence of J waves in leads V1–V3 (Brugada patern) and in leads I, aVL, II, III, aVF, and V4–V6 (Aizawa attern and variant Brugada pattern) is a well-established CG marker associated with the occurrence of fast poymorphic ventricular tachycardia, ventricular fibrillation VF), and sudden death in patients without structural heart isease. However, surprisingly similar ECG patterns can esult from myocardial ischemia and in our experience are ften associated with fatal ventricular arrhythmias as a domnating clinical presentation. Here we present ECGs of even patients with ischemia-induced VF and ischemic J aves during transient coronary artery spasm and acute yocardial infarction (MI).

Electrocardiography and prognosis of patients with acute pulmonary embolism

BACKGROUND To assess the influence of electrocardiographic (ECG) pattern on prognosis and complications of patients hospitalized with acute pulmonary embolism (APE). METHODS We performed a retrospective analysis of 292 patients who had confirmed APE. There were 183 females and 109 males, the age range was 17 to 89 years, and the mean age was 65.4 ± 15.5 years. RESULTS In our study group, there were 33 deaths (mortality rate, 11.3%), and 73 (25%) patients developed complications during hospitalization. Based on European Society of Cardiology risk stratification, we classified 75 (25.7%) patients as high risk, 163 (55.8%) patients as intermediate risk, and 54 (18.5%) patients as low risk. A comparison between patients with complicated APE and those with no complications during hospitalization indicated that the following ECG parameters were more common in patients who had complications: atrial fibrillation, S1Q3T3 sign, negative T waves in leads V2-V4, ST segment depression in leads V4-V6, ST segment elevation in leads III, V1 and aVR, qR in lead V1, complete right bundle branch block (RBBB), greater number of leads with negative T waves, and greater sum of the amplitude of negative T waves. In multivariate analysis, the sum of negative T waves (OR 0.88; p = 0.22), number of leads with negative T waves (OR 1.46; p = 0.001), RBBB (OR 2.87; p = 0.02) and ST segment elevation in leads V1 (OR 3.99; p = 0.00017) and aVR (OR 2.49; p = 0.011) were independent predictors of complications during hospitalization. In turn, in multivariate analysis, only the sum of negative T waves (OR 0.81; p = 0.0098), number of leads with negative T waves [OR 1.68; p = 0.00068] and ST segment elevation in lead V1 (OR 4.47; p = 0.0003) were independent predictors of death during hospitalization. CONCLUSIONS In our population of APE patients, the sum of negative T waves, the number of leads with negative T waves and the ST segment elevation in lead V1 were independent predictors of death during hospitalization. In turn, the sum of negative T waves, the number of leads with negative T waves, and RBBB and ST segment elevation in leads V1 and aVR were independent predictors of complications during hospitalization. We conclude that ECG analysis may be a useful noninvasive method for risk stratification of patients with APE.

Electrocardiographic abnormalities in patients with acute pulmonary embolism complicated by cardiogenic shock

BACKGROUND Cardiogenic shock (CS) is a predictor of poor prognosis in patients with acute pulmonary embolism (APE). OBJECTIVES The aim of this study was to compare electrocardiography (ECG) parameters in patients with APE presenting with or without CS. METHODS A 12-lead ECG was recorded on admission at a paper speed of 25 mm/s and 10 mm/mV amplification. All ECGs were examined by a single cardiologist who was blinded to all other clinical data. All ECG measurements were made manually. RESULTS Electrocardiographic data from 500 patients with APE were analyzed, including 92 patients with CS. The following ECG parameters were associated with CS: S1Q3T3 sign, (odds ratio [OR]: 2.85, P<.001), qR or QR morphology of QRS in lead V1, (OR: 3.63, P<.001), right bundle branch block (RBBB) (OR: 2.46, P=.004), QRS fragmentation in lead V1 (OR: 2.94, P=.002), low QRS voltage (OR: 3.21, P<.001), negative T waves in leads V2 to V4 (OR: 1.81, P=.011), ST-segment depression in leads V4 to V6 (OR: 3.28, P<.001), ST-segment elevation in lead III (OR: 4.2, P<.001), ST-segment elevation in lead V1 (OR: 6.78, P<.01), and ST-segment elevation in lead aVR (OR: 4.35, P<.01). The multivariate analysis showed that low QRS voltage, RBBB, and ST-segment elevation in lead V1 remained statistically significant predictors of CS. CONCLUSIONS In patients with APE, low QRS voltage, RBBB, and ST-segment elevation in lead V1 were associated with CS.

Left ventricular lead implantation at a phrenic stimulation site is safe and effective.

AIMS Phrenic stimulation (PS) is a major limiting factor for both left ventricular (LV) lead placement and cardiac resynchronization therapy (CRT) delivery. We have developed a protocol allowing for LV lead implantation at a PS site based on specific criteria regarding phrenic and LV acute capture thresholds. The present study examined long-term outcomes in patients treated using this protocol. METHODS AND RESULTS A total of 211 consecutive patients underwent CRT device implantation. The procedure was successful in 201 patients. Leads were implanted at a PS site in 27 patients (PS patients) and a non-PS site in 174 patients (non-PS patients). Left ventricular leads were placed at a PS site only on the following conditions: no PS at ≤3.5 V/0.5 ms, LV threshold ≤1.5 V, and a PS/LV threshold ratio >4. The mean PS threshold decreased (5.1 ± 1.6 vs. 2.8 ± 1.6 V, P < 0.001) and the mean LV threshold remained stable (1.0 ± 0.7 vs. 0.9 ± 0.8 V, P = 0.6) in PS patients over the 16 ± 9 month follow-up. Only one PS patient experienced non-reprogrammable PS and required a re-operation. Seven PS patients required very low LV channel output programming without the usual safety margin of twice the LV threshold amplitude or three times the pulse width. However, 100% LV capture was shown in those patients during daily activity. Non-reprogrammable PS occurred in 2 of the 174 non-PS patients. CONCLUSION Our strategy for LV lead implantation at a PS site was found to result in long-term safe and effective outcomes.

Mortality and morbidity in cardiac resynchronization patients: impact of lead position, paced left ventricular QRS morphology and other characteristics on long-term outcome

AIMS To investigate the effect of implantation-related characteristics, especially lead position and left ventricular (LV)-paced QRS morphology, on long-term mortality and morbidity in cardiac resynchronization therapy (CRT) patients. METHODS AND RESULTS The study retrospectively analysed 362 consecutive patients who underwent CRT device implantation over a 6 year period. Pre-implantation, LV-only paced, and biventricularly paced 12-lead electrocardiograms were obtained. Left ventricular and right ventricular (RV) lead positions were determined using biplane fluoroscopy and roentgenograms. The Kaplan-Meier method was used to estimate the survival function for all-cause death/hospitalization and cardiovascular death/hospitalization. Univariate and multivariate Cox proportional hazards models were also applied. The mean follow-up time was 24.7 ± 16.9 months. There were 79 deaths (62 cardiovascular) and 99 unplanned hospitalizations (72 cardiovascular). One year and 2 year all-cause mortality rates were 8.5 and 18.0%, respectively. Electrocardiographic and fluoroscopic descriptors of the LV lead position were found to be predictors of mortality/morbidity (as were functional class, heart failure aetiology, hyponatremia, and chronic atrial fibrillation). In particular, the antero-apical pattern of LV-only paced QRS showed a hazard ratio (HR) of 1.8 in univariate and 1.7 in multivariate analysis for predicting all-cause death/hospitalization (P = 0.006). The apical/paraseptal LV lead position showed an HR of 2.1 in univariate and 1.9 in multivariate analysis for predicting cardiovascular death/hospitalization (P = 0.018). CONCLUSION To achieve better long-term outcomes in CRT patients the antero-apical pattern of LV QRS complexes and apical or paraseptal LV lead position should be avoided.

Relation of atrial fibrillation and right-sided cardiac thrombus to outcomes in patients with acute pulmonary embolism.

Atrial fibrillation (AF) can induce a hypercoagulable state in both the left and right atria. Thrombus in the right side of the heart (RHT) may lead to acute pulmonary embolism (APE). The aim of the study was to determine the prevalence of RHT and AF and to assess their impact on outcomes in patients with APE. The retrospective cohort included 1,006 patients (598 female), with a mean age of 66 ± 15 years. The primary end point was all-cause mortality. The secondary end point was incidence of complications (death, cardiogenic shock, cardiac arrest, vasopressor/inotrope treatment, or ventilatory support). Atrial fibrillation was detected in 231 patients (24%). RHT was observed in 50 patients (5%). The combination of AF and RHT was observed in 16 patients (2%). The overall mortality rate was significantly higher in patients with RHT compared with those without (32% vs 14%, respectively, odds ratio [OR] 3.0, 95% confidence interval [CI] 1.6 to 5.6, p = 0.001). The rate of complications was significantly higher in patients with RHT in comparison to those without (40% vs 22%, respectively, OR 2.4, 95% CI 1.3 to 4.4, p = 0.004). The mortality rate in patients with both AF and RHT was significantly higher in comparison to those with AF but without RHT (50% vs 20%, respectively, OR 3.86, 95% CI 1.3 to 11.2, p = 0.01). In multivariate analysis, RHT (p = 0.03) was an independent predictor of death. In conclusion, AF is a frequent co-morbidity in patients with APE, and the presence of RHT is not uncommon. Among patients with APE, the presence of RHT increases the mortality approximately threefold regardless of the presence of known AF.

T-wave inversion in patients with acute pulmonary embolism: Prognostic value

INTRODUCTION T-wave inversion (TWI) is a common ECG finding in patients with acute pulmonary embolism (APE). OBJECTIVES To determine the prevalence of TWI in patients with APE and to describe their relationship to outcomes. METHODS Retrospective study of 437 patients with APE. TWI patterns were described in two distributions: inferior (II, III, aVF) and precordial (V1-V6). RESULTS TWI was observed in 258 (59%) patients. The mortality rate was significantly higher in the group with TWI in the inferior AND precordial leads compared to the group without TWI (OR: 2.74; p = 0.024) and the group with TWI in the inferior OR precordial leads (OR: 2.43; p = 0.035). As compared those with TWI in <5 leads, patients with TWI in ≥5 leads experienced significantly higher rates of death (17.1% vs. 6.6%, OR: 2.92; p = 0.002) and complications. CONCLUSIONS TWI and the quantitative assessment thereof can be useful to risk stratify patients with APE.

Electrocardiogram in Andersen-Tawil Syndrome. New Electrocardiographic Criteria for Diagnosis of Type-1 Andersen-Tawil Syndrome

Andersen - Tawil syndrome (ATS) is an autosomal - dominant or sporadic disorder characterized by ventricular arrhythmias, periodic paralysis, and distinctive facial and skeletal dysmorphism. Mutations in KCNJ2, which encodes the α-subunit of the potassium channel Kir2.1, were identified in patients with ATS. This genotype has been designated as type-1 ATS (ATS1). KCNJ2 mutations are detectable in up to 60 % of patients with ATS. Cardiac manifestations of ATS include frequent premature ventricular contractions (PVC), Q-U interval prolongation, prominent U-waves, and a special type of polymorphic ventricular tachycardia (PMVT) called bidirectional ventricular tachycardia (BiVT). The presence of frequent PVCs at rest are helpful in distinguishing ATS from typical catecholaminergic polymorphic ventricular tachycardia (CPVT). In typical CPVT, rapid PMVT and BiVT usually manifest during or after exercising. Additionally, CPVT or torsade de pointes in LQTS are faster, very symptomatic causing syncope or often deteriorate into VF resulting in sudden cardiac death. PVCs at rest are quite frequent in ATS1 patients, however, in LQTS patients, PVCs and asymptomatic VT are uncommon which also contributes to differentiating them. The article describes the new electrocardiographic criteria proposed for diagnosis of type-1 Andersen-Tawil syndrome. A differential diagnosis between Andersen-Tawil syndrome, the catecholamine polymorphic ventiruclar tachycardia and long QT syndrome is depicted. Special attention is paid on the repolarization abnormalities, QT interval and the pathologic U wave. In this article, we aim to provide five new electrocardiographic clues for the diagnosis of ATS1.

The ventricular tachycardia score: a novel approach to electrocardiographic diagnosis of ventricular tachycardia.

AIMS Electrocardiographic diagnosis of wide QRS complex tachycardia (WCT) continues to be challenging as none one of the available methods is specific for ventricular tachycardia (VT) diagnosis. We aimed to construct a method for WCT differentiation based on a scoring system, in which ECGs are graded according to the number of VT-specific features. This novel method was validated and compared with Brugada algorithm and other methods. METHODS AND RESULTS A total of 786 WCTs (512 VTs) from 587 consecutive patients with a proven diagnosis were analysed by two blinded observers. The VT score method was based on seven ECG features: initial R wave in V1, initial r > 40 ms in V1/V2, notched S in V1, initial R in aVR, lead II R wave peak time ≥50 ms, no RS in V1-V6, and atrioventricular dissociation. Atrioventricular dissociation was assigned two points, and each of the other features was assigned one point. The overall accuracy of VT score ≥1 for VT diagnosis (83%) was higher than that of the aVR (72%, P = 0.001) and Brugada (81%) algorithms. Ventricular tachycardia score ≥3 was present in 66% of VTs and was more specific (99.6%) than any other algorithm/criterion for VT diagnosis. Ventricular tachycardia score ≥4 was present in 33% of VTs and was 100% specific for VT. CONCLUSION The new ECG-based method provides a certain diagnosis of VT in the majority of patients with VT, identifies unequivocal ECGs, and has superior overall diagnostic accuracy to other ECG methods.