Compression of a giant pseudomeningocele causing transient anoxic seizures-a case report.

Transient anoxic seizure upon application of pressure on a giant pseudomeningocele has never been reported in the literature; such abrupt changes in intracranial pressure due to large volume of cerebrospinal fluid (CSF) translocation, if left untreated may lead to permanent cerebral hypoxic injury and death. Here we describe a case of a 26-year-old woman who had undergone lumbar disc surgery in another unit few months ago and developed a large lump around her back. Any pressure on the lump resulted in headaches and at times episodes of seizures. Clinical examination revealed a very large fluid-filled lump consistent with a giant pseudomeningocele, confirmed by an MRI. A video EEG while applying pressure on the lump was recorded. The patient developed a typical seizure attack with a characteristic pattern of cerebral anoxia, and a paired ECG showed irregular rhythm with junctional and ventricular ectopic beats during the latter part of the attack, raising a suspicion of asystole. Upon relieving the pressure off the lump, the patient gradually regained consciousness with no permanent neurological deficit. We then discuss the pathophysiology of anoxic seizures and highlight the need to be vigilant in managing patients with such lesions in order to prevent permanent cerebral hypoxic injury and death.

Comparison of the origin and coupling interval between ectopy with and without atrial fibrillation initiation.

BACKGROUND: Differentiation of atrial fibrillation (AF) trigger ectopy from other ectopy is often difficult. The purpose of this study was to compare the origin and coupling intervals (CI) between AF-trigger and non-AF-trigger ectopy. METHODS: This study consisted of 120 patients with AF who underwent an initial ablation. Isoproterenol was infused up to 20µg/min to provoke ectopy and AF. We measured the CI of all ectopy provoked by an isoproterenol infusion. The %CI was calculated as the CI of the ectopy/P-P interval of the preceding 2 beats. RESULTS: A total of 117 patients had at least one ectopy, and AF was induced in 56 (47%) patients. Of the 276 ectopies observed in this study, 211 (76%) originated from pulmonary veins and 77 (28%) were AF-trigger ectopy. AF-trigger ectopy more frequently originated from pulmonary veins (PVs) (74 vs. 3, p<0.001) and had a significantly shorter CI (201±70ms vs. 365±147ms, p<0.001) and lower %CI (29±11% vs. 55±14%, p<0.001) than that of non-AF-trigger ectopy. A receiver operating characteristics analysis revealed that a %CI of 40% was the best cut-off value for differentiating whether it was an AF-trigger or not. The identified trigger group, including patients with provoked AF-trigger ectopy or ectopy with a low %CI (<40%), had a significantly better AF recurrence-free survival rate than the other group (88% vs. 65%, p=0.004). CONCLUSIONS: AF-trigger ectopy predominantly originated from PVs and had a short CI. These findings may be useful for estimating whether ectopies are an AF-trigger or not.

[Trigeminy of ventricular bigeminy caused by reentrant mechanism: reentry of reentry]. / Trigeminia de la bigeminia ventricular por mecanismo reentrante: reentrada de la reentrada.

The process that follows an acute myocardial infarction generates an appropriate substrate for the formation of reentry circuits, considered to be the most frequent mechanism of ventricular extrasystoles and tachyarrhythmias. We present the case of a patient with an acute myocardial infarction unusually concurring with ventricular trigeminy coupled to ventricular bigeminated extrasystoles giving rise to a trigeminy sequence over the bigeminy, which indicates the existence of two reentry circuits (reentry of reentry) that trigger ventricular flutter.

Trigeminia de la bigeminia ventricular por mecanismo reentrante: reentrada de la reentrada / Trigeminy of ventricular bigeminy caused by reentrant mechanism: reentry of reentry

El proceso post-infarto agudo de miocardio genera el sustrato apropiado para la formación de circuitos de reentrada, los cuales son considerados como el mecanismo más frecuente de las extrasístoles y taquiarritmias ventriculares. Presentamos el trazado electrocardiográfico de un paciente con infarto agudo de miocardio en quien se observó la inusual concurrencia de una trigeminia ventricular acoplada a extrasístoles ventriculares bigeminadas, que originó una secuencia de trigeminia sobre la bigeminia, evidenciando la existencia de dos circuitos reentrantes (reentrada de la reentrada); después de una dupla de la extrasístole bigeminada se genera un aleteo ventricular.

The process that follows an acute myocardial infarction generates an appropriate substrate for the formation of reentry circuits, considered to be the most frequent mechanism of ventricular extrasystoles and tachyarrhythmias. We present the case of a patient with an acute myocardial infarction unusually concurring with ventricular trigeminy coupled to ventricular bigeminated extrasystoles giving rise to a trigeminy sequence over the bigeminy, which indicates the existence of two reentry circuits (reentry of reentry) that trigger ventricular flutter.

Hisian extrasystole mimicking second degree atrioventricular block. a case report.

Hisian extrasystoles originate from the His bundle. They are rare and usually misdiagnosed. In fact, they manifest on the EKG, with a p' wave located before, in or after the QRS complex. More rarely, the extrasystole blocks the propagation of the influx to the ventricles simulating a Mobitz II atrioventricular (AV) block. We report the case of a 36-Year-old woman with no medical History, suffering from presyncope and palpitations at rest. Her physical examination and EKG were normal. The 24-hour Holter monitoring showed some long periods with unexpected blocked p waves but with no significant pause. Considering her young age and the absence of causes of AV block, we performed an intracardiac electrophysiological study which showed hisian extrasystoles with normal conduction tissue properties at baseline and under flecainide. The diagnosis of hisian extrasystoles simulating Mobitz II AV block was made. A simple monitoring with beta-blockers therapy was recommended. Hisian extrasystoles may simulate first or second degree AV block with different therapeutic and prognostic implications. Nevertheless, these hisian extrasystoles may be the marker of a vulnerable AV conduction, long-term follow up should be considered.

Further insights into blood pressure induced premature beats: Transient depolarizations are associated with fast myocardial deformation upon pressure decline.

BACKGROUND: An acute increase in blood pressure is associated with the occurrence of premature ventricular complexes (PVCs). OBJECTIVE: We aimed to study the timing of these PVCs with respect to afterload-induced changes in myocardial deformation in a controlled, preclinically relevant, novel closed-chest pig model. METHODS: An acute left ventricular (LV) afterload challenge was induced by partial balloon inflation in the descending aorta, lasting 5-10 heartbeats (8 pigs; 396 inflations). RESULTS: Balloon inflation enhanced the reflected wave (augmentation index 30% ± 8% vs 59% ± 6%; P < .001), increasing systolic central blood pressure by 35% ± 4%. This challenge resulted in a more abrupt LV pressure decline, which was delayed beyond ventricular repolarization (rate of pressure decline 0.16 ± 0.01 mm Hg/s vs 0.27 ± 0.04 mm Hg/ms; P < .001 and interval T-wave to peak pressure 1 ± 12 ms vs 36 ± 9 ms; P = .008), during which the velocity of myocardial shortening at the basal septum increased abruptly (ie, postsystolic shortening) (peak strain rate -0.6 ± 0.5 s(-1) vs -2.5 ± 0.8 s(-1); P < .001). It is exactly at this time of LV pressure decline, with increased postsystolic shortening, and not at peak pressure, that PVCs occur (22% of inflations). These PVCs preferentially occurred at the basal and apical segments. In the same regions, monophasic action potentials demonstrated the appearance of delayed afterdepolarization-like transient depolarizations as origin of PVCs. CONCLUSION: An acute blood pressure increase results in a more abrupt LV pressure decline, which is delayed after ventricular repolarization. This has a profound effect on myocardial mechanics with enhanced postsystolic shortening. Coincidence with induced transient depolarizations and PVCs provides support for the mechanoelectrical origin of pressure-induced premature beats.

[Effect of bronchoalveolar lavage on the heart rhythm and conduction of the children with severe pneumonia].

OBJECTIVE: To observe the effect of bronchoalveolar lavage on the heart rhythm and conduction of children with severe pneumonia through monitoring the electrocardiogram change of different step of the bronchoalveolar lavage, for proving the safety of the operation of bronchoalveolar lavage from the perspective of cardiac electrophysiology. METHOD: From July 2011 to March 2012, 30 patients who were hospitalized in pneumology department of Dalian Children's Hospital and met the inclusion criteria and therapeutic indications of bronchoalveolar lavage were chosen. They were 3 to 12 years old, the average age was 5.3 years, including 17 boys and 13 girls, the ratio of boys and girls is 1.3: 1. Continuous sampling the electrocardiogram before and during the process including anesthesia, entering into glottis, lavage, aspiration, and revive, and recording the heart rate, rhythm amplitude and width of P wave, the PR interval, the form and width of QRS complex were also measured. The recorded data were analyzed and statistical analysis to reflect the change of the cardiac electrophysiology. RESULT: The incidence of heart rate increase was 100.0%, 26 (86.7%) patients began to emerge after anesthesia, the rest of the patients also developed heart rate increase after the start of bronchoscopic operation. All patients had sinus tachycardia, and were most obvious in the progress of lavage and revive. In the process of entering into glottis, lavage, aspiration, 13 (43.3%) patients had arrhythmia episodes. Types of arrhythmia included sinus bradycardia, atrioventricular block and premature beat. Incidences of intraoperative arrhythmia compared with the pre- and post-operation were all statistically significantly different (P = 0.00). The most common arrhythmia were premature beat, in 17 of the 30 cases there were premature beat including 9 cases with atrial premature beats and 8 cases ventricular premature contraction. Two patients had III° atrioventricular block accompanied by serious sinus bradycardia. All kinds of arrhythmias except sinus tachycardia disappeared after the operation was ended. Five patients (16.7%) had PR interval prolongation. Five patients (16.7%) had incomplete right bundle branch block (IRBBB) . Incidences of IRBBB compared with the pre-operation and post-operation were all not significantly different [13.3% (n = 4) vs. 0(n = 0) and 3.3% (n = 1), all P > 0.05]. Different operating progress made no significant difference in the measurement value of electrocardiogram[13.3% (n = 4) vs. 0(n = 0) and 3.3% (n = 1), all P > 0.05], but showed the most notable effect on heart rate. CONCLUSION: Bronchoalveolar lavage can influence the heart rhythm and conduction, but most of the influence with pathological significance are transient. Cardiac electrophysiological changes were the most obvious in endotracheal operation with the risk of malignant arrhythmia but the risk is low, the bronchoalveolar lavage technique is safe. The contingency plans for dealing with all kinds of adverse reactions must be ready before the operations of bronchoalveolar lavage. During the procedure, the patient's ECG changes should be closely monitored to reduce the incidence of adverse reactions.

Mobitz type II second-degree atrioventricular block with narrow QRS and junctional extrasystoles: what is the mechanism?

A 74-year-old man underwent an electrophysiological study because of Mobitz type II second-degree atrioventricular (AV) block with narrow QRS and frequent junctional extrasystoles. During the study, there were very frequent single His bundle depolarizations with multiple coupling intervals that reproduce the ECG findings. In this case, some His bundle extrasystoles result in retrograde concealed conduction and prolonged local refractoriness in the AV node that manifest as block of the next atrial impulse.

The effects of simulated obstructive apnea and hypopnea on arrhythmic potential in healthy subjects.

Preliminary evidence supports an association between OSA and cardiac dysrhythmias. Negative intrathoracic pressure, as occurring during OSA, may provoke cardiac dysrhythmias. Thus, we aimed to study the acute effects of simulated apnea and hypopnea on arrhythmic potential and measures of cardiac repolarization [QT(C) and T (peak) to T (end) intervals [TpTec]) in humans. In 41 healthy volunteers, ECG was continuously recorded prior, during and after simulated obstructive hypopnea (inspiration through a threshold load), simulated apnea (Mueller maneuver), end-expiratory central apnea and normal breathing in randomized order. The number of subjects with premature beats was significantly higher during inspiration through a threshold load (n = 7), and the Mueller maneuver (n = 7) compared to normal breathing (n = 0) (p = 0.008 for all comparisons), but not during end-expiratory central apnea (n = 3, p = 0.125). Inspiration through a threshold load was associated with a non-significant mean (SD) increase of the QT(C) interval [+5.4 (22.4) ms, 95 %CI -1.7 to +12.4 ms, p = 0.168] and a significant increase of the TpTcc interval [+3.7 (8.9) ms, 95 %CI +0.9 to +6.6 ms, p = 0.010]. The Mueller maneuver induced a significant increase of the QT(C) interval [+8.3 (23.4) ms, 95 %CI 0.9 to +15.6 ms, p = 0.035] and the TpTec interval (+4.2 (8.2) ms, 95 %CI +1.6 to +6.8 ms, p = 0.002). There were no significant changes of the QT(C) and TpTec intervals during central end-expiratory apnea. These data indicate that simulated obstructive apnea and hypopnea are associated with an increase of premature beats and prolongation of QT(C) and TpTec intervals. Therefore, negative intrathoracic pressure changes may be a contributory mechanism for the association between OSA and cardiac dysrhythmias.

Preliminary study of prospective ECG-gated 320-detector CT coronary angiography in patients with ventricular premature beats.

BACKGROUND: To study the applicability of prospective ECG-gated 320-detector CT coronary angiography (CTCA) in patients with ventricular premature beats (VPB), and determine the scanning mode that best maximizes image quality and reduces radiation dose. METHODS: 110 patients were divided into a VPB group (60 cases) and a control group (50 cases) using CTCA. All the patients then underwent coronary angiography (CAG) within one month. CAG served as a reference standard through which the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTCA in diagnosing significant coronary artery stenosis (luminal stenosis ≥50%) could be analyzed. The two radiologists with more than 3 years' experience in cardiac CT each finished the image analysis after consultation. A personalized scanning mode was adopted to compare image quality and radiation dose between the two groups. METHODOLOGY/PRINCIPAL FINDINGS: At the coronary artery segment level, sensitivity, specificity, PPV, and NPV in the premature beat group were 92.55%, 98.21%, 88.51%, and 98.72% respectively. In the control group these values were found to be 95.79%, 98.42%, 90.11%, and 99.28% respectively. Between the two groups, specificity, sensitivity PPV, NPV was no significant difference. The two groups had no significant difference in image quality score (P>0.05). Heart rate (77.20±12.07 bpm) and radiation dose (14.62±1.37 mSv) in the premature beat group were higher than heart rate (58.72±4.73 bpm) and radiation dose (3.08±2.35 mSv) in the control group. In theVPB group, the radiation dose (34.55±7.12 mSv) for S-field scanning was significantly higher than the radiation dose (15.10±1.12 mSv) for M-field scanning. CONCLUSIONS/SIGNIFICANCE: With prospective ECG-gated scanning for VPB, the diagnostic accuracy of coronary artery stenosis is very high. Scanning field adjustment can reduce radiation dose while maintaining good image quality. For patients with slow heart rates and good rhythm, there was no statistically significant difference in image quality.

Role of sarcolemmal BK(Ca) channels in stretch-induced extrasystoles in isolated chick hearts.

BACKGROUND: It remains unclear whether sarcolemmal BK(Ca) channels in post-hatch chick ventricular myocytes contribute to stretch-induced extrasystoles (SIE), and whether they are stretch-activated BK(Ca) (SAK(Ca)) channels or a non-stretch-sensitive BK(Ca) variant. METHODS AND RESULTS: To determine the role of sarcolemmal BK(Ca) channels in SIE and their stretch sensitivity, an isolated 2-week-old Langendorff-perfused chick heart and mathematical simulation were used. The ventricular wall was rapidly stretched by application of a volume change pulse. As the speed of the stretch increased, the probability of SIE also significantly increased, significantly shortening the delay between SIE and the initiation of the stretch. Application of 100 nmol/L of Grammostola spatulata mechanotoxin 4, a cation-selective stretch-activated channel (SAC) blocker, significantly decreased the probability of SIE. The application of Iberiotoxin, however, a BK(Ca) channel blocker, significantly increased the probability of SIE, suggesting that a K(+) efflux via a sarcolemmal BK(Ca) channel reduces SIE by balancing out stretch-induced cation influx via SACs. The simulation using a cardiomyocyte model combined with a new stretch sensitivity model that considers viscoelastic intracellular force transmission showed that stretch sensitivity in BK(Ca) channels is required to reproduce the present wet experimental results. CONCLUSIONS: Sarcolemmal BK(Ca) channels in post-hatch chick ventricular myocytes are SAK(Ca) channels, and they have a suppressive effect on SIE.

Electrocardiographic changes in hospitalized patients with leptospirosis over a 10-year period.

BACKGROUND: The aim of this study was to investigate the incidence and type of ECG changes in patients with leptospirosis regardless of clinical evidence of cardiac involvement. MATERIAL/METHODS: A total of 97 patients with serologically confirmed leptospirosis treated at the University Hospital for Infectious Diseases "Dr. Fran Mihaljevic" in Zagreb, Croatia, were included in this retrospective study. A 12-lead resting ECG was routinely performed in the first 2 days after hospital admission. Thorough past and current medical history was obtained, and careful physical examination and laboratory tests were performed. RESULTS: Abnormal ECG findings were found in 56 of 97 (58%) patients. Patients with abnormal ECG had significantly elevated values of bilirubin and alanine aminotransferase, lower values of potassium and lower number of platelets, as well as more frequently recorded abnormal chest x-ray. Non-specific ventricular repolarization disturbances were the most common abnormal ECG finding. Other recorded ECG abnormalities were sinus tachycardia, right branch conduction disturbances, low voltage of the QRS complex in standard limb leads, supraventricular and ventricular extrasystoles, intraventricular conduction disturbances, atrioventricular block first-degree and atrial fibrillation. Myopericarditis was identified in 4 patients. Regardless of ECG changes, the most commonly detected infection was with Leptospira interrogans serovar Australis, Leptospira interrogans serovar Saxkoebing and Leptospira kirschneri serovar Grippotyphosa. CONCLUSIONS: The ECG abnormalities are common at the beginning of disease and are possibly caused by the direct effect of leptospires or are the non-specific result of a febrile infection and metabolic and electrolyte abnormalities. New studies are required for better understanding of the mechanism of ECG alterations in leptospirosis.

Cardiac arrhythmias during aerobatic flight and its simulation on a centrifuge.

INTRODUCTION: It is well known that accelerations during centrifuge training and during flight can provoke cardiac arrhythmias. Our study was designed to investigate both the similarities and differences between heart rhythm disturbances during flights and centrifuge tests. METHOD: There were 40 asymptomatic, healthy pilots who performed two training flights and were also tested in a human centrifuge according to a program of rapid onset rate acceleration (ROR) and of centrifuge simulation of the actual acceleration experienced in flight (Simulation). During the flight and centrifuge tests ECG was monitored with the Holter method. ECG was examined for heart rhythm changes and disturbances. RESULTS: During flights, premature ventricular contractions (PVCs) were found in 25% of the subjects, premature supraventricular contractions (PSVCs) and PVCs with bigeminy in 5%, and pairs of PVCs in 2.5% of subjects. During the centrifuge tests, PVCs were experienced by 45% of the subjects, PSVCs and pairs of PVCs by 7.5%, and PVCs with bigeminy by 2.5%. Sinus bradycardia was observed during flights and centrifuge tests in 7.5% of subjects. DISCUSSION: Comparative evaluation of electrocardiographic records in military pilots during flights and centrifuge tests demonstrated that: 1) there were no clinically significant arrhythmias recorded; and 2) the frequency and kind of heart rhythm disturbances during aerobatic flight and its simulation on a centrifuge were not identical and did not occur repetitively in the same persons during equal phases of the tests.