Atrial involvement and progression of sinus node dysfunction in non-senile patients: evidences from electroanatomic mapping and long-term follow-up.

PURPOSE: Sinus node inability or conduction disorders of its surrounding atrial myocardium cause sinus node dysfunction (SND). This study aimed to characterize right atrium (RA) substrates and long-term atrial lead performance after pacemaker implantation in non-senile SND patients. METHODS: Eighteen SND patients (53.3 ± 9.6 years) controlled by 18 age-matched supraventricular tachycardia patients were consecutively enrolled. The P-wave amplitude (PWA) and P-wave duration (PWD) were measured on surface electrocardiography. Electroanatomic mapping was conducted to assess the bipolar voltage, complex signals, volume, and activation time of RA. Pacemaker implantation was performed in SND patients after mapping. RESULTS: Compared with controls, SND patients showed significant PWA reduction (0.13 ± 0.02 vs. 0.16 ± 0.04 mV, p = 0.017) and PWD prolongation (120.8 ± 15.2 vs. 105.2 ± 8.6 ms, p = 0.001). The RA endocardial voltage was lower (1.56 ± 0.78 vs. 2.57 ± 0.55 mV, p < 0.001) and activation time was longer (112.1 ± 14.9 vs. 90.8 ± 12.4 ms, p < 0.001) in the study group. Atrial lead was anchored at the lower atrial septum in one patient and failed in another due to extensive atrial scarring. During a median follow-up of 86 (57-88) months, one patient lost atrial capturing, and overall atrial sensing was significantly decreased (2.44 ± 1.16 vs. 1.87 ± 1.01 mV, p = 0.003). CONCLUSIONS: Atrial involvement was proved and the process was progressive in non-senile SND patients, as demonstrated by diffused RA lower voltage, slower conduction, and the decrease of the atrial lead sensing.

[ECG pearl: sick sinus syndrome mimicking acute coronary syndrome - the aVR-sign]. / EKG-gyöngyszem: acut coronaria szindrómát utánzó sinuscsomó-betegség ­ az aVR-jel.

The aVR-sign can indicate left main or multivessel coronary disease, but the sign is not STEMI eqvivalent and is not a sensitive sign for coronary disese. The following case is an example of this. An 89-year-old woman was admitted with chest pain, atrial fibrillation and multiple lead ST-segment depression but ST-segment elevation in lead aVR. The aVR-sign indicated urgent angiography with negative result. A spontaneous sinus conversion was observed with repolarization normalisation. Later the ECG demonstrated SA-blocks, and sinus arrest. Sick sinus syndrome was diagnosed and the patient was treated with pacemaker and oral anticoagulant. Orv Hetil. 2020; 161(11): 434-436.

Evaluation of cardiac synchrony in left bundle branch pacing: Insights from echocardiographic research.

AIM: The aim of this study is to assess if left bundle branch pacing (LBBP) can preserve physiological cardiac synchrony and deliver favorable hemodynamic effects. METHODS: Consecutive patients undergoing dual chamber pacemaker implantation for sick sinus syndrome (SSS) and a normal cardiac function with a narrow QRS complex were recruited for the study. Electrocardiogram and echocardiographic examinations were performed during ventricular pacing-on and native-conduction modes. The QRS duration (QRSd), systolic dyssynchrony index (SDI), and the standard deviation of time-to-peak contraction velocity in left ventricular (LV) 12 segments (Tsd-12-LV) were measured to evaluate LV synchrony. The stroke volume (SV) and the degree of atrioventricular valvular regurgitation were also assessed. RESULTS: A total of 40 patients underwent LBBP, while another 38 patients underwent right ventricular septum pacing (RVSP) as control group. Baseline characteristics were similar between the two groups. With LBBP, the paced QRSd was slightly wider than the intrinsic QRSd (101.03 ± 8.79 ms vs 91.06 ± 14.17 ms, P < .0001) while the LV mechanical synchrony during LBBP pacing mode was similar to that of native-conduction mode (SDI, 3.14 ± 2.49 vs 2.70 ± 1.68, P = 0.129; Tsd-12-LV, 26.43 ± 15.55 vs 25.61 ± 16.07, P = .671) in the LBBP group. The LV synchrony in the LBBP group was superior to the RVSP group significantly. No significant differences in SV (64.08 ± 16.97 mL vs 65.45 ± 18.68 mL, P = .241) or the degree of atrioventricular valvular regurgitation were noted between LBBP capture and native-conduction modes. CONCLUSION: LBBP could preserve satisfactory LV synchrony and result in favorable hemodynamic effects.

Respuesta al ECG de noviembre de 2017 / Response to ECG, November 2017

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Seizure Triggered by Sick Sinus Syndrome.

Sick sinus syndrome (SSS) is a dysfunction of sinoatrial node resulting in symptomatic bradycardia or sinus pauses causing decreased cardiac output with cerebral hypoperfusion and usually presents as syncope, presyncope or fatigue. The occurrence of a seizure is very rare. A 69-year-old man suffered two episodes of generalised tonic-clonic seizures. MRI and electroencephalogram failed to reveal the cause of seizures. In the emergency room, he experienced presyncope simultaneous to bradycardia and sinus pauses. He was stabilised with atropine and dopamine infusion and underwent definitive therapy with a permanent dual-chamber pacemaker with complete symptom resolution. Diagnostic confounders include convulsive syncope and ictal bradycardia. Syncope may be accompanied by myoclonic jerks (convulsive syncope), but postictal confusion is absent. Bradycardia may be seen during the postictal period (ictal bradycardia syndrome), but protracted sinus dysfunction is not present. Hypoperfusion due to significant SSS triggered seizures in this patient who may have an underlying predisposition.

Comparative Assessment of the Heart's Functioning by Using the Akabane Test and Classical Methods of Instrumental Examination.

Acupuncture physicians have studied the application of reflexotherapy to cardiology. However, no one has investigated the connection of ancient Chinese diagnostic methods with modern tools. A total of 102 patients (54 men and 48 women) with heart pathology, namely, sick-sinus syndrome, Wolff-Parkinson-White syndrome, and atrioventricular blockade, were studied using the usual instrumental methods (transesophageal electrophysiological study of the heart, echocardiography), after which they underwent Akabane thermopuncture testing as in traditional Chinese medicine. The results of cardio examination from one side of the Akabane test with that from the other side were compared by means of a multiple stepwise regression analysis. We revealed the effects on the characteristic pattern of acupuncture channel lesions inherent in a definite heart pathology, i.e., the most vulnerable acupuncture channel (AC), of such factors as disturbances of the contractile, conductive, or automatic heart functions, and changes in the chambers' size or circulation volume. Сhanges in the indices of the left and the right branches of these channels usually reflect the opposing natures of the changes in these indicators, which should be considered in reflexotherapy. The main value of the Akabane test along with the use of mathematical analysis lies in early, quick, and inexpensive detection of the above-mentioned heart disturbances.

The association between left ventricular twisting motion and mechanical dyssynchrony: a three-dimensional speckle tracking study.

Left ventricular (LV) dyssynchrony is a causal factor in LV dysfunction and thought to be associated with LV twisting motion. We tested whether three-dimensional speckle tracking (3DT) can be used to evaluate the relationship between LV twisting motion and dyssynchrony. We examined 25 patients with sick sinus syndrome who had received dual chamber pacemakers. The acute effects of ventricular pacing on LV wall motion after the switch from atrial to ventricular pacing were assessed. LV twisting motion and dyssynchrony during each pacing mode were measured using 3DT. LV dyssynchrony was calculated from the time to the minimum peak systolic area strain of 16 LV imaging segments. Ventricular pacing increased LV dyssynchrony and decreased twist and torsion. A significant correlation was observed between changes in LV dyssynchrony and changes in torsion (r = -0.65, p < 0.01). Evaluation of LV twisting motion can potentially be used for diagnosing LV dyssynchrony.

[Sinus node disease and atrio-ventricular disorders in pregnant women. When temporary or permanent pacing is necessary?]. / Choroba wezla zatokowego i zaburzenia przewodzenia przedsionkowo komorowego u kobiet w ciazy. Czy i kiedy zabezpieczac czasowa lub stala stymulacja?

Sinus node disease and atrioventricularis disorders are very rarely observed in women during pregnancy. Bradyarrhythmia in pregnant women is divided into mild bradycardia connected with pressure on venous cava inferior by growing fetus, new detected AV disorders and existing before pregnancy: AV Ill degree block congenital or after surgery, sinus node disease and channelopathies. Management in bradyarrhythmia in pregnancy is very difficult, despite guidelines. Whenever possible problem should be resolved before pregnancy. When symptomatic AV III degree block with wide QRS complex escape rhythm is observed--the permanent pacing should be considered with echocardiography or electro-anatomical system using. Another option is novel temporary, prolonged pacing.

Prevalence of E/A wave fusion and A wave truncation in DDD pacemaker patients with complete AV block under nominal AV intervals.

AIMS: Optimization of the AV-interval (AVI) in DDD pacemakers improves cardiac hemodynamics and reduces pacemaker syndromes. Manual optimization is typically not performed in clinical routine. In the present study we analyze the prevalence of E/A wave fusion and A wave truncation under resting conditions in 160 patients with complete AV block (AVB) under the pre-programmed AVI. We manually optimized sub-optimal AVI. METHODS: We analyzed 160 pacemaker patients with complete AVB, both in sinus rhythm (AV-sense; n = 129) and under atrial pacing (AV-pace; n = 31). Using Doppler analyses of the transmitral inflow we classified the nominal AVI as: a) normal, b) too long (E/A wave fusion) or c) too short (A wave truncation). In patients with a sub-optimal AVI, we performed manual optimization according to the recommendations of the American Society of Echocardiography. RESULTS: All AVB patients with atrial pacing exhibited a normal transmitral inflow under the nominal AV-pace intervals (100%). In contrast, 25 AVB patients in sinus rhythm showed E/A wave fusion under the pre-programmed AV-sense intervals (19.4%; 95% confidence interval (CI): 12.6-26.2%). A wave truncations were not observed in any patient. All patients with a complete E/A wave fusion achieved a normal transmitral inflow after AV-sense interval reduction (mean optimized AVI: 79.4 ± 13.6 ms). CONCLUSIONS: Given the rate of 19.4% (CI 12.6-26.2%) of patients with a too long nominal AV-sense interval, automatic algorithms may prove useful in improving cardiac hemodynamics, especially in the subgroup of atrially triggered pacemaker patients with AV node diseases.

Percutaneous extraction of inadvertently placed left-sided pacemaker leads with complete cerebral embolic protection.

Lead wire malposition is a known, but rare complication of permanent pacemaker or defibrillator implantation. The actual incidence and prevalence is unknown and management options for inadvertent left ventricular lead malposition have not been uniform. Current recommendations include systemic anticoagulation with warfarin or surgical lead removal with circulatory arrest for compelling clinical scenarios. Percutaneous left-sided lead extraction is contraindicated due to the potentially increased risk of thromboembolic complications associated with this procedure. To our knowledge, this is the first report of percutaneous extraction of inadvertently placed left ventricular and left atrial endocardial pacemaker leads with flow-preserving complete cerebral embolic protection. We also review the current literature regarding the incidence, management, and percutaneous extraction of left-sided cardiac leads.

Correlating hemodynamic magnetic resonance imaging with high-field intracranial vessel wall imaging in stroke.

Vessel wall magnetic resonance imaging at ultra-high field (7 Tesla) can be used to visualize vascular lesions noninvasively and holds potential for improving stroke-risk assessment in patients with ischemic cerebrovascular disease. We present the first multi-modal comparison of such high-field vessel wall imaging with more conventional (i) 3 Tesla hemodynamic magnetic resonance imaging and (ii) digital subtraction angiography in a 69-year-old male with a left temporal ischemic infarct.

HCN4 mutations in multiple families with bradycardia and left ventricular noncompaction cardiomyopathy.

BACKGROUND: Familial forms of primary sinus bradycardia have sometimes been attributed to mutations in HCN4, SCN5A, and ANK2. In these studies, no structural cardiac alterations were reported in mutation carriers. However, a cluster of reports in the literature describe patients presenting with sinus bradycardia in association with left ventricular noncompaction cardiomyopathy (LVNC), pointing to a shared genetic cause. OBJECTIVES: This study sought to identify the genetic defect underlying the combined clinical presentation of bradycardia and LVNC, hypothesizing that these 2 clinical abnormalities have a common genetic cause. METHODS: Exome sequencing was carried out in 2 cousins from the index family that were affected by the combined bradycardia-LVNC phenotype; shared variants thus identified were subsequently overlaid with the chromosomal regions shared among 5 affected family members that were identified using single nucleotide polymorphism array analysis. RESULTS: The combined linkage analysis and exome sequencing in the index family identified 11 novel variants shared among the 2 affected cousins. One of these, p.Gly482Arg in HCN4, segregated with the combined bradycardia and LVNC phenotype in the entire family. Subsequent screening of HCN4 in 3 additional families with the same clinical combination of bradycardia and LVNC identified HCN4 mutations in each. In electrophysiological studies, all found HCN4 mutations showed a more negative voltage dependence of activation, consistent with the observed bradycardia. CONCLUSIONS: Although mutations in HCN4 have been previously linked to bradycardia, our study provides the first evidence to our knowledge that mutations in this ion channel gene also may be associated with structural abnormalities of the myocardium.

The symptom complex of familial sinus node dysfunction and myocardial noncompaction is associated with mutations in the HCN4 channel.

BACKGROUND: Inherited arrhythmias were originally considered isolated electrical defects. There is growing evidence that ion channel dysfunction also contributes to myocardial disorders, but genetic overlap has not been reported for sinus node dysfunction (SND) and noncompaction cardiomyopathy (NCCM). OBJECTIVES: The study sought to investigate a familial electromechanical disorder characterized by SND and NCCM, and to identify the underlying genetic basis. METHODS: The index family and a cohort of unrelated probands with sinus bradycardia were examined by electrocardiography, Holter recording, exercise stress test, echocardiography, and/or cardiac magnetic resonance imaging. Targeted next-generation and direct sequencing were used for candidate gene analysis and mutation scanning. Ion channels were expressed in HEK293 cells and studied using patch-clamp recordings. RESULTS: SND and biventricular NCCM were diagnosed in multiple members of a German family. Segregation analysis suggested autosomal-dominant inheritance of the combined phenotype. When looking for potentially disease-causing gene variants with cosegregation, a novel hyperpolarization-activated cyclic nucleotide channel 4 (HCN4)-G482R mutation and a common cysteine and glycine-rich protein 3 (CSRP3)-W4R variant were identified. HCN4-G482R is located in the highly conserved channel pore domain. Mutant subunits were nonfunctional and exerted dominant-negative effects on wild-type current. CSRP3-W4R has previously been linked to dilated and hypertrophic cardiomyopathy, but was also found in healthy subjects. Moreover, different truncation (695X) and missense (P883R) HCN4 mutations segregated with a similar combined phenotype in an additional, unrelated family and a single unrelated proband respectively, which both lacked CSRP3-W4R. CONCLUSIONS: The symptom complex of SND and NCCM is associated with heritable HCN4 defects. The NCCM phenotype may be aggravated by a common CSRP3 variant in one of the families.

Unusual vanishing interstitial lymphatic "pearls" in a patient presenting with extensive interstitial and mediastinal MDCT features of acute cardiogenic failure related to bradycardia and mitral regurgitation.

Thoracic multidetector computed tomography-MDCT-was simultaneously performed during emergency abdominal CT in a patient presenting with abdominal pain and acute cardiogenic edema related to sick sinus syndrome and mitral prolapse with regurgitation. A constellation of severe but completely reversible interstitial and mediastinal features was found comprising pleural effusions, diffuse alveolar ground glass, thickening of the bronchial walls and septal lines, hazy infiltration of the mediastinal fat, and enlarged lymphatic nodes. Multiple atypical hypodense nodular "pearls" were also found. These oval shape or fusiform pearls were distributed along the thickened septal lines and disappeared completely after treatment. The hypothesis of transient lymphatic ectasia or lakes is proposed for these never previously described abnormalities.

Left atrial responses to acute right ventricular apical pacing in patients with sick sinus syndrome.

Chronic right ventricular apical (RVA) pacing can lead to an increased risk of heart failure and atrial fibrillation, but the acute effects of RVA pacing on left atrial (LA) function are not well known. Twenty-four patients with sick sinus syndrome and intact intrinsic atrioventricular conduction were included. All patients received dual-chamber pacemaker implants with the atrial lead in the right atrial appendage and the ventricular lead in the right ventricular (RV) apex. Transthoracic standard and strain echocardiography (measured by tissue Doppler imaging and speckle tracking image) were performed to identify functional changes in the left ventricle (LV) and LA before and after 1 hour of RVA pacing. The LA volume index did not change after pacing; however, the ratio of peak early diastolic mitral flow velocity (E) to peak early diastolic mitral annular velocity (Ea) was significantly increased and peak systolic LA strain (Sm), mean peak systolic LA strain rate (SmSR), peak early diastolic LA strain rate (EmSR), and peak late diastolic LA strain rate (AmSR) were significantly reduced after RV pacing. LV dyssynchrony, induced by RV pacing, had a significant correlation with E/Ea, Sm, and SmSR after pacing. E/Ea also had a negative correlation with Sm and SmSR after pacing. Multivariate regression analysis identified LV dyssynchrony and E/Ea as important factors that affect Sm, SmSR, EmSR, and AmSR after acute RVA pacing. Acute RVA pacing results in LA functional change and LV dyssynchrony and higher LV filling pressures reflected by E/Ea are important causes of LA dysfunction after acute RVA pacing.