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PubMed2000

Capture of particulate emboli during cardiac procedures in which aortic cross-clamp is used. International Council of Emboli Management Study Group.

BACKGROUND: Previous studies have shown that atheroemboli are associated with neurologic complications following cardiac operation. Additionally, it has been demonstrated that embolization is closely related to the application and removal of ascending aortic cross-clamps. METHODS: A prospective registry of 304 patients was initiated to describe patient selection, procedures, particulate capture, and clinical outcomes after intraaortic filtration in patients undergoing cardiac surgical procedures with cardiopulmonary bypass and median sternotomy. Prior to the removal of the cross-clamp, the intraaortic filter (EMBOL-X Inc, Mountain View, CA) was deployed and left in place until the patient was weaned from extracorporeal circulation. Upon removal, filters were fixed in formalin and shipped to a core laboratory for examination. RESULTS: Mean patient age was 68 years (range 25 to 88 years), 40% had ascending aortic calcification, 59% of the procedures were coronary artery bypass grafting (CABG), 20% were valve replacement or repair, and 12% were a combination of CABG and valve surgery. Aortic cross-clamps were used in nearly all cases (302 of 304 patients); partial clamps were used in 84% of the CABG procedures. To date, 243 filters have been examined. Sixty-two percent of the filters analyzed revealed fibrous atheroma, 2% grumous atheroma, and 6% epiaortic debris. Platelet and fibrin strands were found in 52% of the filters and 22% contained evidence of thrombus or red blood cells. CONCLUSIONS: These findings from the International Council of Emboli Management Registry confirm that particulates are released during cardiac surgical procedures using the aortic cross-clamp. Continued observational and randomized studies are necessary to confirm the clinical relevance of particulate extraction.

Adult↗
PubMed2002

Photodynamic therapy to control fibrosis in human glaucomatous eyes after trabeculectomy: a clinical pilot study.

OBJECTIVE: To evaluate the safety, tolerability, and clinical effect on intraocular pressure (IOP) of a carboxyfluorescein ester as an adjunctive antifibrotic therapy in human glaucomatous eyes to control postoperative wound healing after trabeculectomy. METHODS: In 10 human glaucomatous eyes with high IOPs that underwent 1 to 3 previous surgical procedures for glaucoma, 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester was applied 15 minutes prior to trabeculectomy via a subconjunctival injection followed by intraoperative illumination with diffuse blue light (450-490 nm; approximately 51.9 x 10(3) candelas/m(2)) for 8 minutes. Antifibrotic efficacy was established by clinical response, postoperative IOP reduction, slitlamp examination, and filtering bleb site photographs. Success was defined as an IOP less than 21 mm Hg from baseline without the eye receiving any antiglaucomatous medication or an application of antimetabolites. RESULTS: The mean (SD) IOP on the day before surgery was 37.2 (11.2) mm Hg. The IOP was 16.6 (3.8) mm Hg in 8 successful eyes after a mean (SD) follow-up of 400.1 (38.1) days (P<.001). Two eyes showed scarring at the site of the filtering bleb within 1 month. In 1 eye with pseudoexfoliation glaucoma IOP decreased to 17 mm Hg but needed topical antiglaucomatous medication. Clinical examination revealed none of the following: blebitis, uveitis, endophthalmitis, or toxic damage of the adjacent tissues. CONCLUSIONS: We report our findings about the first 10 consecutive human glaucomatous eyes treated with a single dose of 80 microg of 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester during trabeculectomy. In contrast to chemotherapeutic agents, cellular photoablation acts only on cells having incorporated 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester and having been exposed to light of an appropriate wavelength. Though safety and efficacy demand a controlled randomized study, our method seems to be an effective therapeutic approach to control postoperative fibrosis in human glaucomatous eyes with a poor surgical prognosis. Multiple factors such as dose of light, means of application, wavelength, irradiation area, total dose of the dye, and multiple dosing may be altered in the future to improve the antifibrotic effect of photodynamic therapy during surgery for glaucoma.

Adolescent↗
PubMed2006

Bacteraemia in patients with hidradenitis suppurativa undergoing carbon dioxide laser surgery: detection and quantification of bacteria by lysis-filtration.

BACKGROUND: Hidradenitis suppurativa (HS) is a cicatrising and persistent disease of apocrine gland-bearing areas in adults. The severity of this condition varies from a few suppurating lesions to widespread, disabling disease. The aetiology is obscure, but suggested contributory factors include a genetic predisposition, comedones occluding the pilosebaceous apparatus, bacterial infections, and hormonal factors. Treatment consists mainly of surgery, while medical therapies serve principally as adjunct therapy. OBJECTIVES: The aim of the study was to determine the number and type of bacteria circulating in the bloodstream in patients with HS undergoing surgical treatment with a carbon dioxide laser stripping-secondary intention technique. METHODS: Twenty-one patients (20 females and 1 male, mean age 36, range 20-55 years) were included in the study. One blood sample (8.3 ml) was taken before surgery, one during the operation and the last one 10 min after surgery. Five healthy persons (all females, mean age 36, range 23-48 years) not undergoing any operation were used as the controls. The blood was cultured by a lysis-filtration technique which had been shown to be very sensitive. Since the filter catches the microorganisms and colonies are formed during culturing, the number of bacteria in the samples is easily determined. RESULTS: In 6 patients, all samples were negative, which indicates that the method of surgery itself caused no spread of bacteria from the lesions. Bacterial growth in the first blood sample was found in 9 patients, from the second sample in 10 and from the third one in 6. In 1 patient, bacteria were detected in three samples. At least 12 bacterial species were identified. The dominating bacteria were coagulase-negative staphylococci of which most were subtyped as Staphylococcus warneri. Among the anaerobic microorganisms, Propionibacterium acnes and P.granulosum were the most frequently isolated bacteria. The bacterial findings in the blood samples accord well with the results from a previous study in which cultures were taken from the deep parts of the HS lesions. In the 5 controls, no microbial growth was detected. CONCLUSION: The carbon dioxide laser stripping technique caused no additional spread of bacteria into the bloodstream. The evaluation of cultures containing microorganisms from normal skin flora is controversial. Since the bacteria encountered in this study are in close agreement with the findings in cultures from the deeper parts of HS lesions they seem to be relevant. The growth of bacteria in the first blood sample taken before surgery may indicate that some of these patients have bacteria continuously circulating in their blood.

Adult↗
PubMed1999

Ascending aortic atherosclerosis--a complex and challenging problem for the cardiac surgeon.

Ascending aortic atherosclerosis is an increasingly recognized problem in cardiac surgery. It is the most important risk factor for perioperative stroke and seems to be in part responsible for postoperative neurobehavioral changes. Patients exhibiting ascending aortic atherosclerosis have a significantly reduced survival rate and are at considerable risk for spontaneous embolic stroke during the long-term postoperative course. Preoperative noninvasive diagnosis and intraoperative assessment by inspection or palpation of the aorta are insensitive. Intraoperative epiaortic ultrasound scanning has emerged as a most helpful tool for the diagnosis of ascending aortic atherosclerosis and has revealed major insights into the nature and distribution of this disease. Management strategies range from minimally invasive aortic "no touch" techniques to maximally invasive procedures, including application of deep hypothermic circulatory arrest. Operative modifications in coronary artery bypass grafting include avoidance of aortic crossclamping, alternative methods of aortic crossclamping and placement of all arterial in situ bypass conduits, Y-grafts or extra-anatomical bypass grafts. Other operative strategies include modifications of the arterial cannulation site, replacement of the ascending aorta or ascending aortic endarterectomy. One of the most recently developed methods is embolic capture by intraaortic filters. Increased awareness of ascending aortic atherosclerosis is critical in order to prevent the devastating complications it can cause during cardiac surgery.

Aortic Diseases↗
PubMed1987

New techniques for reducing the thermochemical damage in the course of laser surgery.

New techniques were proposed for reducing the damage incurred to living tissues owing to temperature rise induced by surgical lasers. Precooling of the tissue and spatial filtering were evaluated numerically and were shown to be most effective in most surgical procedures. Application of pulse trains was also evaluated numerically and optimal operating conditions were identified.

Animals↗
PubMed2005

Risk factors for periprocedural complications in carotid artery stenting without filter protection: A serial diffusion-weighted MRI study.

INTRODUCTION: In high-grade stenosis, carotid artery stenting (CAS) may be chosen as an alternative to carotid surgery. Ischemic periprocedural complications may be documented best with diffusion-weighted MRI (DWMRI). In this prospective study serial DW-MRI and color-coded duplex sonography (CCDS) were used to identify carotid stenosis, which is associated with an increased risk of ischemic events due to CAS. METHODS: High resolution DW-MRI were performed in 74 out of 77 patients before and after CAS. All MRI scans were analyzed in a blinded manner. With CCDS each carotid stenosis was evaluated according to the grade, length, echo properties and plaque surface. RESULTS: In 42 out of 74 patients (56.8 %) a total of 188 new procedure- related DWI-lesions could be detected, while in 32 patients MRI-controls remained normal. Of the lesions 79.25 % had a size < 1 cm. In one major and two minor strokes due to CAS (total complication rate 3.9 %) corresponding territorial infarcts could be demonstrated. A highly significant correlation was found between the length of the stenosis and the incidence of new DWI-lesions (p = 0.0141). In contrast, neither the grade of ICA stenosis nor the sonographic plaque morphology or plaque surface correlated with the number of DWI-lesion in postinterventional scans. CONCLUSIONS: The length-and not the degree-of an ICA stenosis seems to be the most decisive sonographic factor for estimating the periprocedural risk of embolism. DWI-lesions are much more frequent than clinical complications and may represent an important surrogate marker for improving the techniques of carotid artery stenting, especially comparing the benefit of different mechanical protection devices.

Aged↗
PubMed1979

The value of measuring intravascular platelet aggregates in the prediction of postoperative pulmonary dysfunction.

A modified Swank screen filter technique was used to investigate, first, whether intravascular platelet aggregates (IPA) could be detected in patients immediately after surgery and then, the relationship between IPA levels and postoperative pulmonary function. The test, as modified, achieved an excellent reproducibility (r = 0.95) and a close correlation with the number of aggregates identified in samples of femoral vein blood by subsequent scanning electron microscopy (r = 0.93). In 20 patients IPA levels were measured 30 min and 3 h after surgery and pulmonary function (arterial PO2, physiological dead space and alveolar/arterial PO2 gradient) was evaluated preoperatively and on days 1 and 7 postoperatively. Patients with elevated IPA levels suffered a greater mean fall in arterial PO2 at 7 days (1.8 kPa) than did patients with normal IPA levels (0.6 kPa) (P less than 0.05). This was explained by a marked increase in the pulmonary arteriovenous shunt as indicated by the alveolar/arterial PO2 gradient (2.3 kPa v. 0.4 kPa, P less than 0.01). Those patients with increased pulmonary shunting and arterial hypoxia 1 week after surgery also had a greater fall in the platelet count on the first postoperative day. The screen filtration technique is a reproducible test which measures IPA accurately and may be used to predict pulmonary function 1 week later. This suggests that treatment to inhibit IPA may reduce postoperative pulmonary dysfunction.

Humans↗
PubMed1995

Detrimental effects of perioperative blood transfusion.

Evidence suggests that perioperative allogeneic blood transfusion increases the risk of infectious complications after major surgery and of cancer recurrence after curative operation. This has been attributed to immunosuppression. Several authors have suggested that filtered whole blood and/or red cell concentrate, or leucocyte- and buffy coat-reduced red cells in artificial medium or their own plasma, may reduce postoperative immunosuppression. It was also anticipated that the use of autologous blood might minimize the risk of perioperative transfusion, but studies have unexpectedly shown similar postoperative infectious complications and cancer recurrence and/or survival rates in patients receiving autologous blood donated before operation and those receiving allogeneic blood. Future studies should identify common risk factors associated with blood storage.

Blood Transfusion↗
PubMed2003

[Comparison of Healon, Healon GV, and Healon 5 in viscotrabeculectomy].

BACKGROUND: The aim of this study was to determine the efficacy of three viscoelastics of different viscosities in preventing early postoperative complications after trabeculectomy (TE) and phacotrabeculectomy (PT). METHODS: One hundred seventy-one eyes of 149 consecutive patients underwent TE or PT. In all cases, Healon, Healon GV, or Healon 5 was instilled in the anterior chamber at the beginning of surgery and left there at the end. RESULTS: Four hours postoperatively, the mean intraocular pressure (IOP) in all groups was below 13 mmHg (27.4 mmHg preoperatively) and did not rise above 13 mmHg in the first postoperative week. Postoperative IOP spikes did not occur in any group. Healon remained in the anterior chamber up to 4 days after surgery, Healon GV up to 6 days, and Healon 5 up to 9 days. Characteristic early postoperative complications of filtering procedures, such as choroidal detachment, shallow anterior chamber, iridocorneal contact, hyphema, and bleb failure, were not observed in our patients. CONCLUSION: All three viscoelastics reduced early postoperative complications with comparable efficacy and without IOP spikes.

Adult↗
PubMedDate not supplied

The role of leukocyte depletion in reducing injury to myocardium and lung during cardiopulmonary bypass.

Activated leukocytes and oxygen free radicals have been implicated in the pathogenesis of heart and lung injury after reperfusion and during cardiopulmonary bypass. This study was designed to determine whether leukocyte depletion prevents injury to the heart and lung during cardiopulmonary bypass. Twenty-eight open heart surgeries were performed in this study. In Group F, leukocyte depletion was performed with an LG-6 arterial line filter after aortic declamp (n = 14). Leukocyte depletion was not performed during cardiopulmonary bypass in Group C (n = 14). Thereafter, cardiac and lung function were assessed in the 24 hr after reperfusion. The total catecholamine dose used for 24 hr after reperfusion (r) was 61.9 +/- 13.4 in Group C and 43.9 +/- 19.2 in Group F (p < 0.05). CK-MB at 3 and 6 hr after reperfusion was 65.9 +/- 13.5 and 64.8 +/- 15.8 in Group C and 45 +/- 11.8 and 38 +/- 10.8 in Group F, respectively (p < 0.05). The pulmonary index after reperfusion at 3 and 6 hr was 1.7 +/- 0.5 and 1.3 +/- 0.4 in Group C and 0.7 +/- 0.3 and 0.6 +/- 0.4 in Group F, respectively (p < 0.05). There was significantly better preserved lung function in Group F. In conclusion, leukocyte depletion was significantly effective in preserving heart and lung function during cardiopulmonary bypass.

Adult↗
PubMed2001

Telesurgical laparoscopic radical prostatectomy. Initial experience.

INTRODUCTION: Telepresence surgery offers theoretically to overcome two main problems of laparoscopic surgery, i.e. the limitation to only four degrees of freedom and the lack of stereovision. Since 1998, telesurgical minimally invasive procedures have been performed with the da Vinci system mainly for cardiac bypass surgery. Clinical experience in urology is still very limited. We want to present our initial experience using the device for robot-assisted laparoscopic radical prostatectomy. MATERIAL AND METHODS: The Intuitive surgical system consists of two main components: the surgeon's viewing and control console with 3D imaging and the surgical arm unit that positions and maneuvers detachable surgical instruments. These instruments introduced via two 8-mm trocars allow movements in all 6 degrees of freedom due to the EndoWrist technology. The surgeon performs the procedure seated at the console holding specially designed instruments. Highly specialized computer software and mechanics transfer the surgeon's hand movements exactly to the microsurgical movements of the manipulators at the operative site. We have used a semilunar-shaped 5-trocar arrangement with the robot's arms at the lateral trocars and two assistant trocars medially. A sixth trocar was used in the right suprapubic area for retraction of the gland. The left assistant used different instruments such as bipolar forceps, Ultracision, Endoclip, whereas the right assistant mainly used the suction-irrigation device. Except the first case, the Intuitive System was attached after exposure of Retzius' space. RESULTS: We have treated 6 patients (2 pT2, 4 pT3, median Gleason score 6). The OR time averaged 315 (242-480) min including pelvic lymph node dissection. No intraoperative complications occurred, 1 patient required transfusions. There were no positive margins, median catheter time was 5 days. 3 patients were completely continent after 1 month. CONCLUSION: Telerobotic laparoscopic surgery offers several advantages over all presently available techniques, such as all six degrees of freedom, dexterity enhancement, tremor filtering, and stereovision. There is a learning curve with the device, mainly because of the magnification, the 3D image and the lack of tactile feedback. However, only after a short period of time, the experienced surgeon is able to get familiar with the device. However, there are still concerns with respect to the high investment and running costs of the device as well as regarding the necessity of further developments of instruments for urological procedures.

Aged↗
PubMed1978

[Trabeculectomy-iridencleisis combined with cataract extraction].

On 31 eyes (23 patients, average age 74 years) with cataract and primary open-angle or chronic angle-closure glaucoma modified trabeculectomy with lobelike iridencleisis was performed combined with cataract-extraction. They were followed up for periods between 6 months and 3 years. In 84% of cases the i.o. pressure continued to be normalized without further antiglaucomatous therapy, in 16% additional treatment with drugs achieved sufficient lowering of i.o. pressure. In nearly all of the cases I observed a diffuse, very flat filtering bleb. Gonioscopy shows, that filtering channels stay open along the margin of the imbedded iris flap. Complications were rare and demanded no further surgery.

Aged↗
PubMed1995

[Congenital anomalies of the inferior vena cava: role of imaging].

In recent years, clinics and radiology of congenital anomalies of the inferior vena cava have increased in importance in planning abdominal surgery, liver or kidney transplantation, or new interventional or diagnostic procedures such as the positioning of inferior vena cava filters to prevent pulmonary embolism, varicocel sclerotherapy and renal venous sampling. In the past, the radiologic assessment of these rare anomalies was performed only with angiography, which remains the most accurate diagnostic method. Today, besides angiography, less invasive examinations can be performed, e.g., US, CT and MRI, with MRA. In the last two years, 5 patients with inferior vena cava anomalies were examined: 3 had double inferior vena cava and 2 azygos continuation. All of them were submitted to US, CT, MRI and MRA and 3 patients underwent also angiography, two of them with double puncture. US can suggest the diagnosis but may be limited by technical factors and in the assessment of the whole inferior vena cava. Enhanced CT can depict anomaly extent, but uses contrast agents and ionizing radiations. Angiography better depicts craniocaudal spread and collateral networks but is an invasive procedure and sometimes needs a double puncture (double inferior vena cava). MRI, with MRA, yields the same information as the other modalities, but without contrast agents or ionizing radiations. The development of velocity encoded sequences will probably make this technique the method of choice in the study of inferior vena cava anomalies. Our study was aimed at reviewing the embryo-genesis of inferior vena cava anomalies and to assess the relative importance of different diagnostic procedures in the diagnosis and staging of these anomalies.

Aged↗
PubMed2007

Deep vein thrombosis due to migrated graft bone after posterior lumbosacral interbody fusion. Case report.

The authors report the case of an 83-year-old woman with refractory sciatica attributable to isthmic spondylolisthesis at L-5. Her symptoms were successfully improved after posterior lumbar interbody fusion (PLIF) at L5-S1; however, notable swelling in her left leg suddenly developed 2 days postoperatively. Anterior migration of a fragment of bone graft was demonstrated on computed tomography scanning, and there was obvious occlusion of the left common iliac vein (CIV) on magnetic resonance venography. Ultrasonography revealed a thrombus in the left CIV at the site of compression. To prevent a pulmonary embolism during manipulation of the affected vein, an inferior vena cava filter was placed just before excision of the migrated bone fragment. The swelling in the patient's leg subsided quickly after the surgery, and she was treated with heparin and warfarin to prevent recurrent deep vein thrombosis (DVT). Six months after the second surgery, complete restoration of blood flow to the left CIV and no recurrence of DVT were demonstrated on magnetic resonance venography. Especially in elderly patients with degenerative disc disease, excessive curettage and impaction of disc materials during the PLIF procedure may cause migration of bone graft fragments. Surgeons should be aware of the possible vascular complications of PLIF.

Aged, 80 and over↗
PubMed1994

Lethal pulmonary embolism in a patient with primary antiphospholipid syndrome and a vena caval filter.

A 61-year old Hispanic woman with a history of primary antiphospholipid syndrome with pulmonary emboli and who was status post a vena caval filter placement to prevent recurrent pulmonary emboli, presented with acute onset of right upper quadrant abdominal pain. Acute cholecystitis was diagnosed and she underwent a surgically uncomplicated cholecystectomy. The postoperative course was complicated by new, massive pulmonary emboli despite prophylactic treatment with aspirin and low-dose heparin. Patient died en route to surgery for emergency embolectomy. This case suggests that a regimen of low-dose heparin and aspirin therapy in patients with primary antiphospholipid syndrome and a previously placed vena caval filter is not effective in preventing postoperative thromboembolic complications; more aggressive anticoagulation therapy is required.

Antiphospholipid Syndrome↗
PubMed2001

Release of interleukin-10 by reinfusion of salvaged blood after knee arthroplasty.

OBJECTIVES: To determine whether the method of the autotransfusion in association with knee arthroplasty leads to differences in anti-inflammatory cytokines in the patient's circulation. DESIGN AND SETTING: Prospective study in a university hospital. PATIENTS: Twenty-one patients undergoing knee arthroplasty were randomized into two groups assigned to postoperative blood salvage. Seven patients received postoperatively filtered salvaged blood, and seven received centrifuged and washed salvaged blood. Patients with postoperative blood loss less than 400 ml (n=7) did not receive any transfusion. MEASUREMENTS AND RESULTS: Plasma levels of interleukin (IL) 1beta, IL-4, and IL-10 and of polymorphonuclear leukocyte elastase were measured by enzyme-linked immunosorbent assay. The plasma concentration of IL-10 was elevated after reinfusion of salvaged blood in all groups 1 day after surgery (p<0.05). Plasma IL-6, IL-10, and PMN elastase was higher (p<0.01) in all groups 1 day after surgery than preoperatively. There were significantly higher plasma levels 1 min after retransfusion of IL-6 (p<0.01) and IL-10 (p<0.05) in patients receiving filtered blood than in those receiving centrifuged and washed salvaged blood. CONCLUSION: Total knee arthroplasty results in the release of interleukin-10. Transfusion of filtered salvaged blood leads to higher levels of cytokines IL-6 and IL-10 than after transfusion of washed and centrifuged salvaged blood.

Aged↗
PubMed1994

Talc deposition in skin and tissues surrounding silicone gel-containing prosthetic devices.

BACKGROUND AND DESIGN: Periprosthetic capsule formation is the most common cause of morbidity associated with silicone gel-filled breast implants. All implant recipients develop capsules. However, the extent of capsule formation varies greatly among patients, ranging from a thin flexible membrane to a constrictive inelastic band of sclerotic collagen. Although silicone gel bleed has been proposed as the most likely cause of excessive capsular sclerosis, liquid silicone did not induce fibrosis in early clinical trials. Because many implant modifications have been introduced since the original studies were performed, a more plausible explanation for excess capsular sclerosis is the inadvertent introduction of a fibrogenic contaminant. The skin and periprosthetic tissues removed from 41 women during implant revision surgery were examined for the presence of foreign substances that might contribute to capsular sclerosis. Tissue was examined histologically with and without polarizing filters and with scanning electron microscopy equipped for energy-dispersive x-ray analysis. RESULTS: A high incidence of talc was found within the skin and tissues adjacent to silicone-containing breast prostheses. Birefringent talc crystals, identified in 71% of the patients, were observed within nodular granulomas and perivascular histiocytes. Two specimens containing talc crystals were analyzed by energy-dispersive roentgenographic analysis, which confirmed the identity of the crystalline material as talc. Among 10 capsules examined by direct immunofluorescence, there was no evidence of immune complex deposition. CONCLUSIONS: The high incidence of talc deposition in the skin and tissues surrounding silicone implants suggests that talc either is introduced at the time of implant surgery (possibly in association with the silicone elastomer bag, tissue sizers, or surgical gloves) or is released into the tissues as a silicone gel contaminant during gel bleed. Talc, a known sclerosing agent, may contribute to periprosthetic fibrosclerosis.

Adult↗
PubMed1995

Role of late potentials in identifying patients at risk for ventricular tachycardia after surgical correction of congenital heart disease.

This study evaluates the role of late potentials in identifying patients with sustained ventricular tachycardia (VT) after surgery for congenital heart defects using right ventriculotomy. Nine patients with early (1 to 12 months) or late VT (spontaneous in 7 [induced during electrophysiologic study in 6 of the 7] and induced in 2) and 104 patients without VT were studied. All patients had complete right bundle branch block. Late potentials were quantified by 3 time-domain parameters of the signal-averaged electrocardiogram: total filtered QRS duration, root-mean-square voltage in the last 40 ms, and low-amplitude signal duration of the terminal filtered QRS complex. Root-mean-square voltage filtered at 80 to 250 Hz was lower in patients with than without VT (9 +/- 6 vs 16 +/- 8 microV, p < 0.01). By multivariate analysis, more complex surgery (i.e., insertion of extracardiac conduits, Kawashima operation, etc.), lower root-mean-square voltage, and higher Lown grade (2 to 5) of ventricular arrhythmias on routine postoperative Holter recordings were the only independent predictors of VT (p < 0.001, < 0.05, and < 0.05, respectively). A combination of more complex surgery, root-mean-square voltage < 14 microV, and Lown grade 2 to 5 ventricular arrhythmias was highly predictive of VT (positive predictive value 75%). Conversely, patients without complex surgery and with root-mean-square voltage of > 13 microV were not likely to develop VT (negative predictive value 100%). Late potentials are an independent predictor of VT and may improve the identification of patients at low and high risk of VT after surgery for congenital heart defects using right ventriculotomy.

Action Potentials↗