Determination of effects of internal countershock by direct cardiac recordings during normal rhythm

1986 ◽  
Vol 250 (5) ◽  
pp. H736-H740
Author(s):  
P. G. Colavita ◽  
P. Wolf ◽  
W. M. Smith ◽  
F. R. Bartram ◽  
M. Hardage ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Superior Vena ◽  
Vena Cava ◽  
Low Frequency ◽  
Computer Assisted ◽  
Constant Voltage ◽  
Cardiac Electrical Activity ◽  
Mapping System ◽  
Mapping Techniques

Recording cardiac electrical activity after a countershock has been limited by amplifier saturation. Modifications to our computer-assisted mapping system allowed us to record electrical activity from 56 epicardial electrodes within 5 ms of the end of a countershock. Modifications included the use of solid-state switches to disconnect the filter section of the amplifiers during the shock and changing the low-frequency response of the amplifiers from 0.1 to 10 Hz to filter out large, low-frequency potentials after the shock. Six-millisecond truncated exponential shocks were delivered between the superior vena cava and right ventricular apex through a quadripolar catheter during normal rhythm in seven dogs. As shocks of increasing voltage were delivered during the T-Q interval, progressively more of the epicardium was directly depolarized. A shock of 109 +/- 17 (SD) V directly depolarized the entire epicardium. Shocks of constant voltage were then delivered with increasing prematurity during diastole. As the ventricles became more refractory with increasing shock prematurity, the amount of epicardium depolarized became progressively less. Thus computer-assisted mapping techniques are capable of measuring the area depolarized by a shock during normal rhythm and may be useful during arrhythmias to improve our understanding of defibrillation and cardioversion.

scholarly journals Antiarrhythmic Properties of Elsholtzia ciliata Essential Oil on Electrical Activity of the Isolated Rabbit Heart and Preferential Inhibition of Sodium Conductance

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 948
Author(s):  
Regina Mačianskienė ◽  
Lauryna Pudžiuvelytė ◽  
Jurga Bernatonienė ◽  
Mantė Almanaitytė ◽  
Antanas Navalinskas ◽  
...  
Keyword(s):  
Essential Oil ◽  
Electrical Activity ◽  
Rabbit Heart ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cardiac Electrical Activity ◽  
Surface Ecg ◽  
Elsholtzia Ciliata ◽  
Qrs Duration ◽  
Mapping Techniques

Elsholtzia ciliata essential oil (E. ciliata) has been developed in Lithuania and internationally patented as exerting antiarrhythmic properties. Here we demonstrate the pharmacological effects of this herbal preparation on cardiac electrical activity. We used cardiac surface ECG and a combination of microelectrode and optical mapping techniques to track the action potentials (APs) in the Langendorff-perfused rabbit heart model during atrial/endo-/epi-cardial pacing. Activation time, conduction velocity and AP duration (APD) maps were constructed. E. ciliata increased the QRS duration and shortened QT interval of ECG at concentrations of 0.01–0.1 μL/mL, whereas 0.3 μL/mL (0.03%) concentration resulted in marked strengthening of changes. In addition, the E. ciliata in a concentration dependent manner reduced the AP upstroke dV/dtmax and AP amplitude as well as APD. A marked attenuation of the AP dV/dtmax and a slowing spread of electrical signals suggest the impaired functioning of Na+-channels, and the effect was use-dependent. Importantly, all these changes were at least partially reversible. Our results indicate that E. ciliata modulates cardiac electrical activity preferentially inhibiting Na+ conductance, which may contribute to its effects as a natural antiarrhythmic medicine.

scholarly journals Feasibility of surgical procedures of invasive thymoma invading the neighbouring organs

2019 ◽  
Vol 6 (7) ◽  
pp. 2645
Author(s):  
Ajay Kumar ◽  
Jiang Ge Ning
Keyword(s):  
Superior Vena ◽  
Adult Population ◽  
Vena Cava ◽  
Radical Resection ◽  
Invasive Disease ◽  
Invasive Thymoma ◽  
Thymic Epithelial Tumors ◽  
Anterior Compartment ◽  
Staging Systems

Thymomas are the commonest anterior mediastinal compartment neoplasm, which constitutes about 20 and 50% respectively of all mediastinal and anterior compartment tumors occurring in the adult population. The various staging systems of thymomas have been defined on the basis of the degree of invasiveness. According to the WHO classification, there are six histological types of thymic epithelial tumors. The most important prognostic factor is the stage according to Masaoka’s system. The treatment of thymomas involves combinations of surgery, radiation, and chemotherapy. The determination of which combination is chosen is reflected mostly by the stage of the disease. In the case of invasive disease, radiation therapy is often used as adjuvant treatment. Although invasive thymoma commonly infiltrates neighbouring mediastinal structures, its extension into the superior vena cava (SVC) and consequent SVC occlusion are rare. In this kind of cases, the urgent removal of the thymoma and radical resection of the tumour infiltrating the SVC represents the reasonable option. 

scholarly journals Endocardial and epicardial activation maps for three-dimensional-perimitral flutter using a three-dimensional mapping system: A case report

2021 ◽  
Author(s):  
Tomoyuki Arai ◽  
Masao Takahashi ◽  
Rintaro Hojo ◽  
Seiji Fukamizu
Keyword(s):  
Superior Vena ◽  
Three Dimensional ◽  
Vena Cava ◽  
Posterior Wall ◽  
System A ◽  
Three Dimensional Mapping ◽  
Mapping System ◽  
Conduction Pathway ◽  
Linear Ablation ◽  
Total Activation

Abstract Background Perimitral flutter (PMF) is a macro-reentrant tachycardia, and mitral isthmus (MI) linear ablation is considered to be the preferable mode of treatment. Additionally, PMF can sometimes develop via epicardial connections, including coronary sinus and vein of Marshall. However, there are no reports of three-dimensional (3 D) atrial tachycardia (AT) via the intramural tissue. Case summary A 78-year-old man underwent catheter ablation for paroxysmal atrial fibrillation and AT, including pulmonary vein isolation, left atrial posterior wall isolation, superior vena cava isolation, and MI linear ablation in a total of four procedures. However, AT reoccurred, and he underwent a fifth procedure for AT. Although the MI block line was complete in both the endocardial and epicardial voltage maps, AT indicated PMF. The total activation time did not cover all phases of tachycardia cycle length due to the conduction pathway through the intramural muscle/bundles that could not be mapped with the addition of epicardial mapping. The tachycardia was terminated by ablation at the mitral valve annulus in the 2 o'clock position, where the bundles might have been attached. Discussion Both endocardial and epicardial activation maps indicated 3 D-PMF, whose circuit included the intramural muscle and bundles in a tachycardia circuit. It is necessary to recognise AT, which is involved via intramural tissues.

Characteristics of the electrical activity within the persistent left superior vena cava: Comparative view with reference to the ligament of Marshall

2003 ◽  
Vol 36 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Mitsunori Maruyama ◽  
Takeshi Ino ◽  
Shinjiro Miyamoto ◽  
Takeshi Tadera ◽  
Hirotsugu Atarashi ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Left Superior Vena Cava ◽  
Persistent Left Superior Vena

Dissociated electrical activity in the superior vena cava after pulmonary vein cryoballoon ablation

2018 ◽  
Vol 30 (1) ◽  
pp. 136-137 ◽  
Author(s):  
Takashi Nakashima ◽  
Nobuhiro Takasugi ◽  
Yuki Sahashi ◽  
Hiromitsu Kanamori ◽  
Hiroaki Ushikoshi ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Pulmonary Vein ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Cryoballoon Ablation

scholarly journals Presence of dipalmitoylphosphatidylcholine from the lungs at the active hydrophobic spots in the vasculature where bubbles are formed on decompression

2016 ◽  
Vol 121 (3) ◽  
pp. 811-815 ◽  
Author(s):  
Ran Arieli ◽  
Soliman Khatib ◽  
Jacob Vaya
Keyword(s):  
Blood Vessels ◽  
Superior Vena ◽  
Bubble Formation ◽  
Lung Surfactant ◽  
Vena Cava ◽  
Dramatic Improvement ◽  
Decompression Illness ◽  
Lung Surfactants ◽  
Main Component

Most severe cases of decompression illness are caused by vascular bubbles. We showed that there are active hydrophobic spots (AHS) on the luminal aspect of ovine blood vessels where bubbles are produced after decompression. It has been suggested that AHS may be composed of lung surfactant. Dipalmitoylphosphatidylcholine (DPPC) is the main component of lung surfactants. Blood samples and four blood vessels, the aorta, superior vena cava, pulmonary vein, and pulmonary artery, were obtained from 11 slaughtered sheep. Following exposure to 1,013 kPa for 20.4 h, we started photographing the blood vessels 15 min after the end of decompression for a period of 30 min to determine AHS by observing bubble formation. Phospholipids were extracted from AHS and from control tissue and plasma for determination of DPPC. DPPC was found in all blood vessel samples and all samples of plasma. The concentration of DPPC in the plasma samples ( n = 8) was 2.04 ± 0.90 μg/ml. The amount of DPPC in the AHS which produced four or more bubbles ( n = 16) was 1.59 ± 0.92 μg. This was significantly higher than the value obtained for AHS producing less than four bubbles and for control samples ( n = 19) (0.97 ± 0.61 μg, P = 0.027). DPPC leaks from the lungs into the blood, settling on the luminal aspect of the vasculature to create AHS. Determining the constituents of the AHS might pave the way for their removal, resulting in a dramatic improvement in diver safety.

Detection and quantification of small right-to-left shunts by the phase-plane method

1984 ◽  
Vol 247 (4) ◽  
pp. H517-H522
Author(s):  
A. Fonseca-Costa ◽  
P. Magrassi ◽  
W. A. Zin ◽  
L. J. Romeo
Keyword(s):  
Phase Plane ◽  
Superior Vena ◽  
Vena Cava ◽  
Indicator Dilution ◽  
Initial Portion ◽  
Plane Method ◽  
Anesthetized Dogs ◽  
Phase Plane Method ◽  
Dilution Curves

In six anesthetized dogs 70 indicator-dilution curves and phase-plane plots were recorded. Indocyanine green was injected into the superior vena cava and sampled through a dichromatic cuvette densitometer from the femoral artery. Dye-dilution curves were recorded from dogs with normal cardiovascular systems and repeated after right-to-left shunts of different magnitude were surgically produced. The percent of blood shunting was calculated according to standard indicator-dilution equations and also by means of oximetric determination of blood samples. They were compared with shunt estimates based on phase-plane loop measurements. Good correlation was found with standard indicator-dilution procedures (r = 0.890) but not with oximetry (r = 0.466). The phase plane shows its utility in the detection and evaluation of small right-to-left shunts. These shunts affect the initial portion of the phase plane and the alterations appear to be more evident than in the corresponding concentration-vs.-time curves.

scholarly journals Empirical superior vena cava isolation in patients undergoing redo- catheter ablation procedure after recurrence of atrial fibrillation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
F Spies ◽  
A Madaffari ◽  
G Voellmin ◽  
P Krisai ◽  
N Schaerli ◽  
...  
Keyword(s):  
Catheter Ablation ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Success Rates ◽  
Electroanatomic Mapping System ◽  
Kaplan Meier ◽  
Mapping System ◽  
Af Recurrence

Abstract Background/Introduction Extra pulmonary vein (PV) foci may trigger AF recurrence after an initially successful PVI. Superior vena cava (SVC) catheter ablation (CA) may therefore offer a treatment target in order to improve success rates. Purpose The purpose of this study was to evaluate the potential benefit of empirical SVC isolation in addition to PVI in patients undergoing a second CA after index PVI. Methods We retrospectively analyzed consecutive patients scheduled for a second CA because of a recurrence of symptomatic AF. Redo-CA was performed with a 3D electroanatomic mapping system and point-by-point ablation using RF energy in the range between 25 W and 30 W. In case of persistent isolation of all PVs, only SVCI was performed. In case of reconnection of vein(s), a wider antral re-isolation was performed. Redo-PVI (PVI-group) or Redo-PVI plus SVC isolation (SVCI) (PVIplusSVCI-group) were performed at the discretion of the operator. No additional targets were allowed. The endpoint of all procedures was elimination of the PV signals confirmed by a circular mapping catheter at the level of the PV ostium and elimination of all signals in the SVC in case of SVCI. Recurrence of AF during a follow-up of 12 months is presented. Results We analyzed 191 patients (age 61±10 years, 30% female, BMI 27±5 kg/m2, LVEF 56±9%, PLAX 41±7 mm, paroxysmal 61%). Whereas 148 (78%) patients underwent Redo-PVI only, 31 patients (16%) underwent PVI plus SVCI, and in 12 patients (6%) SVCI only was performed. Baseline characteristics did not differ significantly between the two groups. In the PVI-group, 79% were recurrence-free compared to 65% (see Kaplan-Meier curve: log rank p=0.011) in the PVIplusSVCI-group. The RF time of the PVI group focusing on the wide antral re-isolation of vein(s) was significantly higher than for the PVIplusSVCI-group (819±494 s versus 458±444 s; p<0.001). Conclusion Additional empirical SVCI at redo-PVI in patients with symptomatic AF recurrence does not lead to an increase in freedom from AF recurrence. Focusing on an additional “wider antral” re-isolation may be more effective. Kaplan-Meier Survival Curves for Recurre Funding Acknowledgement Type of funding source: None

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