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Biomedical subjects

G Van Nooten

Publications and source records attributed to G Van Nooten.

At least 19 recordsLinked to original sources
PubMed2003

Off-pump coronary surgery: surgical strategy for the high-risk patient.

OBJECTIVE: In a retrospective study, we compared two groups of consecutive patients operated by the same team during the year 2000 for coronary artery disease with the use of extracorporeal circulation (group 1, n=230) or on the beating heart using the Octopus II plus stabiliser (group 2, n=228). High-risk patients were identified by a EuroSCORE plus 6. EuroSCORE definitions and predicted risk models were utilized to compare the variables of the groups. METHODS: There were no significant differences between the preoperative variables of the groups in age, gender, left ventricular function, diabetes and peripheral vascular and renal disease as is indicated by the Euroscore (resp. 4.7/5.1 p=0.107). Calcification of the ascending aorta and chronic obstructive lung disease were statistically significant more prevalent in the beating heart group. No differences in preoperative variables in the high-risk patients group (Euroscore 8.5/8.1 p=0.356) except for calcification of the ascending aorta. RESULTS: All patients underwent a full revascularisation through a midline sternotomy. Significant more distal anastomoses were performed in group 1 (3.7 per patient (1-6)) with regard to group 2 (2.9 per patient (1-6)). Anesthesia, postoperative treatment and follow up were equal for both groups. A significant lower incidence of atrial fibrillation (p=0.010), shorter ICU stay (p=0.031) and renal insufficiency (p=0.033) was reported in group 2. In the low risk group, we could not diagnose any difference between the two groups, except for atrial fibrillation. The benefits of the beating heart surgery however were more pronounced in the high-risk patient as is indicated by a significant reduction of the ICU stay by 1 day (3.5d/2.5d (p=0.028)), better preservation of the renal function (p=0.017) and a significant reduction of the length of hospital stay by more than two days (p=0.040). A lower incidence of atrial fibrillation, however not significant. CONCLUSION: In our experience, beating heart surgery is a safe alternative for conventional coronary heart surgery. High-risk patients do benefit most from this technique. It became our first choice in the elderly patient and patients presenting with higher co-morbidities.

Acute Kidney Injury↗
PubMed2003

An experimental model of coronary anastomosis without suturing.

OBJECTIVE: The aim of the study is to explore the feasibility and mid-term patency of an easier anastomotic technique for Minimally Invasive Direct Coronary Bypass Grafting (MIDCAB). METHODS: Eight mongrel dogs (+/-15 kg) underwent direct anastomosis between the left internal thoracic artery (LITA) and the left anterior descending coronary artery (LAD) via inferior sternotomy on the beating heart. After positioning the graft, the distal part of the LAD was opened to allow retrograde filling of the LITA-graft. The anastomosis was secured by the use of biological glue (BioGlue, Cryolife, Marietta, GA, USA). No intravascular suture material was used. Ischemic time averaged 6 min. The proximal LAD was occluded upstream the arteriotomy. All survivors were angiographically controlled for patency after 6-8 weeks. Consequently, four dogs were sacrificed after 6 weeks and the remaining after 3 months for anatomo-pathological and histological examination by light and electron microscopy of the anastomotic site. RESULTS: All procedures were successful except for one animal that died of uncontrollable bleeding at the anastomotic site. Another sustained post-operative transmural anterior myocardial infarction due to a late graft occlusion. All angiographically controlled grafts were patent with two vascular strings near the anastomotic site. Histology showed early macrophage infiltration into the glue. At post-mortem examination, new endothelialization was noticed in 80% of the cases. However, ultrastructural examination detected marked differences in endothelial fibroblastic lining compared to normal histology. CONCLUSIONS: Good mid-term permeability of the LITA grafts was observed in this new anastomotic technique for MIDCAB in the canine model. Although neo-endothelialization was present in most cases, ultrastructural differences were noticed after 3 months in the neo-intima compared to normal.

Anastomosis, Surgical↗
PubMed2002

Tissue factor as the main activator of the coagulation system during cardiopulmonary bypass.

OBJECTIVE: This study investigates the influence of foreign material and blood aspirated from nonvascular structures on activation of coagulation, hemolysis, and blood loss. METHODS: The series comprises 3 randomized groups (groups C, S, and S+P) of 10 patients undergoing routine coronary artery bypass grafting with cardiopulmonary bypass. In group C, the control group, all aspirated blood was returned into the circulation. In group S suction blood was discarded, whereas group S+P was identical to group S, with surfaces coated with phosphorylcholine. Plasma concentrations of beta-thromboglobulin, thrombin generation, haptoglobin, and free hemoglobin, as well as blood loss, were measured. RESULTS: A steady increase in free plasma hemoglobin, as well as an increased generation of thrombin, was noticed in group C. Moreover, a close correlation (r = 0.916) between the generation of thrombin and its inhibition (thrombin-antithrombin complexes) was observed. Platelets were clearly activated in group C and, to a lesser extent, in group S. In contrast, platelet activation in group S+P was negligible, resulting in a 30% decrease in blood loss (P =.05). CONCLUSIONS: Aspirated blood contaminated by tissue contact is the most important activator of the coagulation system and the principal cause of hemolysis during cardiopulmonary bypass. Contact with a foreign surface is not a main variable in the procoagulant effect of bypass. Mimicking the outer cell membrane structure resulted in decreased platelet activation and decreased blood loss.

Aged↗
PubMed2002

Omnicarbon 21 mm aortic valve prosthesis: in vitro hydrodynamic and echo-Doppler study.

The aim of this study was to perform combined hydrodynamic and Doppler echocardiographic tests of the Omnicarbon 21 mm cardiac valve in aortic position in our Pulse Duplicator System for simultaneous assessment of valve performance and valve leakage data. During forward flow conditions, measured mean pressure gradients are between 4.5 and 20.2 mmHg (11.9 +/- 4.4 mmHg) for cardiac outputs between 3.6 and 5.3 /min (4.5 +/- 0.4 /min). Doppler-derived mean pressure gradients are between 2.0 and 170 mmHg (9.3 +/- 3.9 mmHg) for the same flow conditions. Effective Orifice area is 1.31 +/- 0.08 cm2 and the performance index is 0.74 +/- 0.04, using the actual geometric orifice area, and 0.38 +/- 0.02, using the tissue annulus diameter, for a cardiac output of 4.5 +/- 0.4 l/min. Regurgitation volumes are below 3 ml. There is a trend to an effect of valve orientation on hemodynamics.

Aortic Valve↗
PubMed2002

Evaluation of different paediatric venous cannulae using gravity drainage and VAVD: an in vitro study.

Six different commercially available paediatric venous cannulae, together with a specially constructed cannula, were tested in vitro for their pressure-flow relationship. With the cannulae placed in an open reservoir, flow increased with larger diameters and higher pressures. At a pressure of 30 cm H2O, flows were 219 +/- 20, 285 +/- 13, 422 +/- 11 and 728 +/- 4 ml/min for the 12, 13.2, 14 and 16 French, respectively. No differences were found between angled and straight cannulae. When the cannulae were tested in a latex model simulating the right atrium and vena cavae, the highest flow obtained by gravity was 164 ml/min using an angled 14-French cannula. When vacuum was applied to augment venous return, a maximum flow of 179 ml/min was measured using an angled 14-French cannula. Collapse can occur when the pressure difference becomes too high in the test system. This is important, since most children are selectively cannulated in both major veins. Monitoring of the intravascular pressure might help to prevent collapse. A larger-diameter venous cannula does not always produce the highest flow when placed in a vein. This is most obvious when augmenting venous return. The design of the cannula tip, in combination with VAVD, can affect the venous return.

Catheterization↗
PubMed2001

Redo mitral surgery using the Estech endoclamp.

BACKGROUND: Redo-CABG surgery remains extremely hazardous in the presence of open bypass grafts. In our patients with mitral valve pathology with open and well-functioning bypass grafts, we explored alternative approaches in order to avoid damage to the grafts by extensive dissection and direct clamping of the ascending aorta. The "Estech procedure," which uses the Estech remote access perfusion (RAP) endoclamp catheter (Estech Inc., Danville, CA), was selected for these patients. METHODS: From January 1998 to January 2000, 10 patients underwent an Estech procedure for redo mitral surgery. All patients had previous cardiac operations such as coronary artery bypass grafting (CABG) and/or mitral valve procedures. The Estech procedure consisted of an anterior left thoracotomy and peripheral cannulation at femoral site using the Estech endovascular balloon technique. The series was comprised of seven mitral valve replacements, two valve reconstructions, and one closure of a paravalvular leak. One procedure had to be converted to a standard re-sternotomy due to extreme arteriosclerosis of the descending aorta with plaque dislocation at the time of catheter insertion. However, no damage was inflicted to the open bypass grafts. RESULTS: The follow-up period ranged from six to 30 months and was 100% complete. We encountered one hospital death in our group, which was due to a late post-operative intestinal infarction and multiple organ failure (MOF), and was not procedure related. As expected, morbidity was high in this compromised cohort, but no late death has occurred prior to submission of this article. All survivors progressed to an acceptable NYHA functional class. CONCLUSION: The excellent results in this complex patient group inspired us to use the Estech procedure as a standard approach for redo mitral surgery.

Coronary Artery Bypass↗
PubMed2000

Phosphorylcholine coating of extracorporeal circuits provides natural protection against blood activation by the material surface.

OBJECTIVE: The aim of this study is to evaluate the use of a new coating, mimicking the outer cell membrane, in paediatric cardiac surgery. METHODS: Two groups of ten patients with a body weight below 8 kg, undergoing elective cardiac operations for different congenital anomalies, were prospectively enrolled in this study. In one group the whole extracorporeal circuit, including the cannulas, was coated with phosphorylcholine (PC). In the second group the same circuit was used without coating. Platelet activation (thromboxane B2 (TXB2), beta-thromboglobulin (betaTG)), activation of the coagulation system (F1+2), leukocyte activation (CD11b/CD18) and terminal complement activation (TCC) were analyzed pre-cardiopulmonary bypass (CPB), at 15, 60 min of CPB, at the end of CPB, 20 min post CPB and at postoperative day 1 and 6. RESULTS: No statistical differences were found for F1+2 and CD11b/CD18. After onset of CPB mean levels of TCC remained stable in the PC group whereas an increase was observed in the control group. During CPB betaTG values in both groups increased to a maximum at the end of CPB. Within groups the increase in betaTG levels during CPB was statistically significant (P<0.05) from baseline in the control group starting from 60 min of CPB whereas no statistical difference was observed in the PC group. After the start of CPB TXB2 mean levels increased to 405+/-249 pg/ml in the PC group vs. 535+/-224 pg/ml in the control group. After this initial increase there was a small decline in the PC group with further increase. This was in contrast to the control group were TXB2 levels further increased up to a mean of 718+/-333 pg/ml at the end of CPB (P=0.016). CONCLUSIONS: Phosphorylcholine coating had a favourable effect on blood platelets, which is most obvious after studying the changes during cardiopulmonary bypass. A steady increase of TXB2 and betaTG was observed in the control group, whereas plateau formation was observed in the phosphorylcholine group. Clinically, this effect may contribute to reduced blood loss and less thromboembolic complications. Complement activation is lower in the coated group.

Blood Coagulation↗
PubMed1999

The influence of low afterload on the nature of the stress-velocity relationship.

OBJECTIVES: Correct assessment of contractility by conventional methods during manipulation of afterload is often disappointing. To this purpose, the stress-velocity relationship offers assessment of contractility at different levels of afterload. We decided to study the influence of afterload on the nature of the stress-velocity relation. BACKGROUND: Although linear at baseline conditions in a population older than two years, data in newborns or after administration of low-dose dobutamine suggest a different nature of this relationship at low afterload. METHODS: Ten healthy piglets (five to six weeks; 11 to 13 kg) were studied. End-systolic meridional wall stress (ESWS) and rate-corrected velocity of circumferential fiber shortening (VcFc) were measured in these piglets at baseline, after balloon occlusion of the descending aorta, and at nitroprusside infusion rates of 1, 2 and 5 microg/kg/min. To eliminate inotropic influences mediated by reflex tachycardia, we subsequently studied five piglets and six adult pigs after bilateral cervical vagotomy. RESULTS: The ESWS changed from a baseline mean of 50 g/cm2 to 137 g/cm2 after balloon occlusion and to 19 g/cm2 at 5 microg/kg/min of nitroprusside. The VcFc changed from 1.19 c/s (circumference/second) to values of 0.9 c/s and 1.73 c/s, respectively. The ensuing stress-velocity regression line proved to be curvilinear instead of linear. The steeper slope at low afterload could suggest enhanced contractility compared to expected values had the relationship been linear. CONCLUSIONS: Data from young piglets and adult pigs suggest a curvilinear relationship of the stress-velocity relationship. This could probably explain some of the "hypercontractile states" encountered in conditions with low afterload.

Age Factors↗
PubMed1999

Stentless or stented aortic valve implants in elderly patients?

OBJECTIVE: To assess differences in indication and mid-term results between stentless and stented procedures in elderly patients, we followed aortic valve patients over a period of 5 years. METHODS: In a consecutive series of 154 elderly aortic patients in regular sinus rhythm from 1992 to 1997, we inserted 103 stentless (Toronto SPVTM, St Jude Medical Inc., St Paul, Minneapolis, MN) and 51 stented (Carpentier-Edwards supra annular porcine, Baxter Inc., Irvine, CA) bioprostheses in the aortic position. RESULTS: All 154 patients seemed preoperatively eligible for a stentless procedure. Mean age was 74.8 years (range 67-86 years) with a majority of female patients. The surgeon's (in)experience, major dilatation or calcifications of the ascending aorta and aberrant coronary anatomy were the most common reasons for drawback from the stentless procedure (51/154 patients). Aortic clamp time was significantly higher in the stentless vs. stented group (70 vs. 57 min, P < 0.0001). The large average 25.3 mm size of the stentless prostheses (vs. 23.7 mm stented) stands in full contrast with the low mean body surface area of 1.68 m2 (vs. 1.70 m2) of the patients. We encountered. respectively. 5 and 2 hospital-deaths (P = n.s.). The follow-up period ranged from 6 to 66 months and was 97% complete, yielding, respectively, 302 and 139 patient-years. Survival (Kaplan-Meier method) was statistically higher in favor of the stentless procedures (log rank: P = 0.03). All survivors progressed markedly to a mean postoperative NYHA class 1.3 respectively, 1.4 (vs. preop. 3.3 and 3.2). Echocardiographic transvalvular gradients compared favorable for the stentless group in the small under 25 mm valves (P = 0.02 for 23 mm sized valves between groups) with improved left ventricular function and a significant decrease of left ventricular end diastolic diameter (LVEDD 48.0 vs. 56.5 mm) at 1 year follow-up. Cusp calcifications on control echocardiography were detected earlier (beyond 3 years) in the stented group, without signs of early significant regurgitation or dysfunction in both groups, except for one patient necessitating re-operation. CONCLUSION: Although the implantation technique is much more demanding for stentless procedures, reflected by a longer aortic clamp-time, and remains impossible in some cases, elderly, small sized patients take full benefit of their large, non-obstructive prostheses.

Aged↗
PubMed1999

Feasibility of a pumpless extracorporeal respiratory assist device.

BACKGROUND: Our study evaluated the efficacy and feasibility of a pumpless respiratory assist device and determined its capacity for carbon dioxide removal. METHODS: In five adult pigs the left femoral vein and artery were cannulated with a 20F cannula and connected to a low-pressure hollow-fiber artificial lung. After we had obtained baseline values of mean arterial pressure, cardiac output, and blood flow across the artificial lung, the mean arterial pressure was reduced 20% and 40% relative to baseline; in a second phase, it was raised 20% and 40. Cardiac output and artificial lung flow were simultaneously recorded. We determined the carbon dioxide removal capacity of the artificial lung by gradually increasing the arterial partial carbon dioxide tension of the animal. RESULTS: An increase of 10 mm Hg in mean arterial pressure resulted in an increase of flow of 0.14 L/min. The mean pressure drop across the artificial lung was measured at 17 +/- 9 mm Hg. The shunt flow over the artificial lung varied between 14 and 25% of the cardiac output of the animal. Depending on inlet conditions, carbon dioxide removal by the artificial lung was between 62 +/- 22 mL/L/min and 104 +/- 25 mL/L/min. CONCLUSIONS: A pumpless respiratory assist device can remove a significant proportion of the metabolic carbon dioxide production. However, adequate mean arterial pressure is mandatory to maintain sufficient flow across the device. The technique seems attractive because of its simplicity and can be used in acute lung injury in conjunction of apneic oxygenation for prolonged respiratory support.

Airway Resistance↗
PubMed1999

Contractility in humans after coronary artery surgery.

BACKGROUND: Propofol's unique pharmacokinetic profile offers advantages for titration and rapid emergence in patients after coronary artery bypass graft (CABG) surgery, but concern for negative inotropic properties potentially limits its use in these patients. The current study analyzed the effect of various propofol plasma concentrations on left ventricular (LV) contractility by means of a single-beat contractile index based on LV maximal power (PWR(max)). METHODS: The study was conducted in 30 patients after CABG surgery. Immediately after admission to the intensive care unit (ICU), four different plasma concentrations of propofol 0.65, 1.30, 1.95, and 2.60 microg/ml were established. At each concentration level, the cardiac and vascular effects of propofol were studied by combining echocardiographic data with invasively derived aortic root pressure. Preload was characterized by LV end-diastolic dimensions. Afterload was indicated in terms of indexed systemic vascular resistance (SVRI), LV end-systolic meridional wall stress (LV-ESWS), and arterial elastance (Ea). Quantification of effects on contractility was achieved by preload-adjusted PWRmax. RESULTS: Myocardial contractility did not change during a fourfold increase in propofol plasma concentration. Preload-adjusted PWRmax amounted to 3.90+/-1.75 W x ml(-2) x 10(4), 3.98+/-1.69, 3.94+/-1.70, and 3.88+/-1.72, respectively (mean+/-SD). With respect to ventricular loading conditions, propofol caused a significant reduction in both pre- and afterload. CONCLUSIONS: The current results strongly suggest that propofol lacks direct cardiac depressant effects. Nevertheless, meaningful vascular actions of propofol could be demonstrated. Significant decreases in ventricular loading conditions accounted for a marked decrease in arterial blood pressure and supported the concept that propofol in clinically relevant concentration is a vasodilator.

Coronary Artery Bypass↗
PubMed1999

Nitric oxide donors attenuate increase in pressure drop across membrane oxygenators.

We have evaluated the effect of nitric oxide (NO) on the pressure drop across a membrane oxygenator in one in vitro model and two in vivo models (using four dogs and five pigs). In all the experiments sodium nitroprusside (SNP) was used as a NO source, whereas gaseous NO was only used in the in vitro model. The drugs were given when the pressure drop or resistance across the device increased to at least twice the baseline values. In the in vitro model, both SNP and gaseous NO decreased the pressure drop to 75% of its peak value after 10 min and to 67% after 20 min. In the dog model, resistance decreased from 390 to 153 mmHg/l/min after 5 min and to 85 mmHg/l/min after 20 min for a baseline value of 75 mmHg/l/min. The initial resistance across the membrane oxygenator in the pig model increased from 6.6+/-1.3 to 74+/-38 mmHg/l/min. An infusion of 10 microg/kg/min SNP reduced the resistance to 16+/-5 mmHg/l/min.

Animals↗
PubMed1999

Deformation of the stentless porcine valve scaffold enhances accelerated leaflet fibrosis and calcification in juvenile sheep.

Stent mounting of xenografts induces a loss of mobility and reduces the effective valve orifice. By contrast, the higher surgical technical expertise required for stentless procedures is a major obstacle for many surgeons. To facilitate the insertion of the Toronto SPV (St Jude Medical Inc, St Paul, Minneapolis, MN) stentless aortic valve, we tried to alter the porcine design by lowering the invasive profile at the depth of the sinuses on both coronary sites. This technique could theoretically facilitate implantation of the modified stentless valve with an easygoing single-layer suture at the challenging subcoronary level and make it more attractive for the surgeon. The standard model was modified by lowering the profile at the depth of the sinuses on both coronary sites, whether by plication (in 3 specimens, one of each size) or excision (in 3 others) of the protruding porcine aortic wall at the nadir of each coronary sinus. Animal implants in juvenile sheep (6 standard Toronto versus 6 modified valves of 21, 23, and 25 mm) were studied for durability and biocompatibility for 3 to 6 months. All valves were evaluated by postoperative echocardiography and after explantation examined macroscopically, radiographically, histologically, and electron microscopically. The standard valves performed well, although at 6 months after implantation, marked fibrosis was found at the outflow parts with scattered calcifications, essentially in the porcine aortic wall. The leaflets remained mobile and contained scant mineralization. By contrast, the modified specimen showed markedly accelerated fibrosis and significant cusp calcifications at distance from the altered zones. Severe restriction of the mobility of the leaflets was visible 3 months after implantation in the juvenile sheep model. The more pronounced the deformation of the modified scaffold, the faster and more intense the degradation and calcification of the leaflets far from the altered zones (worse in the heavily deformed, plicated cusps). Because all valve types were prepared by identical preservation techniques, this study shows that loss of mobility by distortion of the natural scaffold induces early failure. It is extremely important to correct implantation of stentless valves to prevent early degeneration.

Age Factors↗
PubMed1999

In vivo evaluation of a phosphorylcholine coated cardiopulmonary bypass circuit.

A complete phosphorylcholine coated cardiopulmonary bypass circuit, including the Dideco D901 oxygenator, was tested for gas transfer, blood path resistance, and biocompatibility in a standardized setting. Blood compatibility was tested by measuring complement and platelet activation. Three dogs (mean body weight 28 +/- 3 kg) were placed on cardiopulmonary bypass at a flow rate of 600 mL/min during 6 hours. The animals were weaned from cardiopulmonary bypass and sacrificed electively after 7 days. Oxygen and carbon dioxide transfer were 26.6 +/- 2.4 mL/min and 33.0 +/- 1.9 mL/min, respectively. Mean pressure drop across the oxygenator was 52.6 +/- 0.2 mmHg. The respective baseline values for thromboxane B2, prostaglandin E2 and platelet factor 4 were 1817 +/- 283 pg/mL, 12783 +/- 2109 pg/mL, and 0.35 +/- 0.08 IU/mL. Thromboxane B2 and prostaglandin E2 increased slightly to 2881 +/- 868 pg/mL and 18083 +/- 3144 pg/mL at 30 minutes of bypass, whereas platelet factor 4 values remained stable curing the procedure. Concentrations of complement split products C5a were only mildly increased. After use scanning electron microscopy was performed on the inner housing, heat exchanger, and outer surface of the hollow fibers. No thrombi nor organized cellular deposits were found on any of the components. Phosphorylcholine coating of CPB seems to be very promising regarding platelet activation and complement activation.

Animals↗
PubMed1998

Variations of autonomic tone preceding onset of atrial fibrillation after coronary artery bypass grafting.

Assessment of autonomic tone preceding the onset of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) with heart rate variability was examined in 64 patients scheduled for elective CABG (days 2 to 5). Ninety-six-hour Holter tapes were analyzed in each patient and all events labeled by an experienced technician. The hour preceding AF was divided into 4 quarters (heart rate variability calculated per quarter) and compared with similar time episodes from the group without AF. Twenty-six of 64 patients (40%) had a total of 35 episodes. Only increased age (68+/-5 vs 62+/-9 years) and lower ejection fraction (66+/-16% vs 73+/-8%) were associated with an increased risk for AF. Before onset, a greater number of atrial premature complexes was observed. The standard deviation of all RR intervals (SDNN) showed an increase in the group with AF in the last 15 minutes (significant vs controls and within the AF group). The low-frequency/high-frequency ratio was significantly lower in patients in the first 30 minutes, followed by an increase mainly because the high-frequency spectrum became less important. Thus, initiation of postoperative AF is influenced by autonomic tone variations. A shift in the autonomic balance with a loss of vagal tone and a moderate increase in sympathetic tone are observed before the onset of AF compared with those in controls.

Aged↗
PubMed1998

Analysis of the P wave with signal averaging to assess the risk of atrial fibrillation after coronary artery bypass surgery.

P wave signal averaging was performed in 91 consecutive patients undergoing coronary artery bypass grafting to detect patients at risk of postoperative atrial fibrillation (AF). Sixteen patients (17.5%) developed AF after surgery. The P wave duration on the signal-averaged electrocardiogram (ECG) and on surface ECG was prolonged in AF patients compared to others (respectively 141 +/- 12 vs. 132 +/- 12 ms and 124 +/- 9 vs. 113 +/- 9 ms). The root mean square voltages (RMS) of the total P wave were not different between the two groups; the RMS of the late portion of the P wave (late RMS) was significantly higher (0.25 +/- 0.15 vs. 0.17 +/- 0.10 microV) and the RMS of the first 110 ms of the P wave (early RMS) significantly lower (0.88 +/- 0.28 vs. 1.09 +/- 0.33 microV) in AF. The late/ early RMS ratio was different (0.29 +/- 0.16 vs. 0.17 +/- 0.11). In a multivariate analysis only age and the late/early RMS ratio were predictive for AF.

Adult↗