Mite diversity (Acari: Tetranychidae, Tydeidae, Iolinidae, Phytoseiidae) and within-tree distribution in citrus orchards in southern Spain, with special reference to Eutetranychus orientalis.

Mite diversity of selected citrus orchards in Andalusia (southern Spain) was studied during 2002-2007. The following species were found: Eutetranychus orientalis, Tetranychus urticae, Panonychus citri (Tetranychidae), Tydeus californicus, Lorryia formosa (Tydeidae), Pronematus ubiquitus (Iolinidae), Euseius stipulatus, Typhlodromus phialatus, Neoseiulus californicus, Euseius scutalis, Phytoseiulus persimilis, Paraseiulus talbii and Neoseiulus cucumeris (Phytoseiidae). Eutetranychus orientalis was the dominant tetranychid species in orange and lemon trees, whereas T. urticae was slightly more abundant in mandarines. The most abundant tydeid in clementine and orange was Tydeus californicus, in lemon it was L. formosa. The iolinid P. ubiquitus was found in very low numbers. With respect to phytoseiids, E. stipulatus was dominant in the three citrus species. Eutetranychus orientalis had a unimodal phenology, peaking only in autumn, whereas the other two tetranychids had two maxima. Tydeus californicus showed one or two peaks depending upon the citrus species, and E. stipulatus also had two peaks, one in spring and one in autumn. The mites displayed a non-random distribution in the tree. Eutetranychus orientalis preferred the outer and upper leaves. On the contrary, tydeids (mainly T. californicus) and phytoseiids (mainly E. stipulatus) preferred inner and lower leaves. These preferences had not been sufficiently described previously, and they are important for sampling plans.

Fragmentation of the paced QRS complex: a marker of antitachycardia pacing effectiveness among ICD patients.

INTRODUCTION: The presence of notches in the paced QRS complex (P-QRS) from the right ventricular apex (RVA) reflects delays in the activation of the left ventricle and may therefore be associated with longer times of stimulus conduction. Our objective was to determine prospectively the relationship between the duration of a notch ≥0.1 mV in the P-QRS (DN) and the effectiveness of antitachycardia pacing (ATP). METHODS AND RESULTS: We followed 286 implantable cardioverter-defibrillator (ICD) patients with left ventricular dysfunction (pacing site: RVA) for 41 ± 27 months. ICD programming was standardized. P-QRS (100 bpm) was obtained at implant (50 mm/s). A total of 955 monomorphic ventricular tachycardias (VTs) with a cycle length of 335 ± 32 milliseconds occurred consecutively in 108 patients. ATP was successful in 84% of VTs. DN correlated with the probability of ineffective ATP (C = 0.67; P < 0.001), the cutoff point with the best sensitivity and specificity being 50 milliseconds. The adjusted mean ATP effectiveness per patient was 76% (95% CI: 72-85). Patients with a DN ≥ 50 milliseconds had a lower ATP efficiency: 67% (56-77) versus 92% (87-97) and a higher proportion of VTs terminated with shocks (SH): 31% (21-42) versus 8% (2-14); P < 0.001 for both. Although the occurrence of VT was similar (41% vs. 40%), the incidence of VT-related SH was higher in patients with a DN ≥ 50 (25% vs. 14%; P = 0.01) in the overall study population (n = 286). CONCLUSIONS: When ATP is applied to the RVA, a DN ≥ 50 milliseconds is associated with a lower ATP effectiveness and a higher risk of SH due to VT.

Morphology of far-field electrograms and antitachycardia pacing effectiveness among fast ventricular tachycardias occurring in ICD patients: a multicenter study.

INTRODUCTION: Fast ventricular tachycardias (FVT) are less likely to be terminated by antitachycardia pacing (ATP). No information is available regarding the ability of far-field electrogram (Ff-EG) morphology (Ff-EGm) in predicting the result of the subsequent ATP. Our objective is to determine the relationship between Ff-EGm and ATP efficacy. METHODS AND RESULTS: In this multicenter study we analyzed 289 FVT (cycle length [CL]: 250-320 milliseconds) occurring consecutively in 52 ICD patients with Medtronic devices (LVEF: 37 ± 6; pacing site: right ventricular apex). FVT programming was standardized, including a single ATP burst as initial therapy. The configuration of Ff-EG was HVA versus HVB. FVTs were classified in QFVT or non-QFVT according to the presence or absence of a negative initial deflection in the Ff-EG. The mean CL was 291 ± 24 milliseconds. We observed 4 Ff-EGm: QS (n = 14, 5%), QR (n = 158, 55%), R (n = 93, 32%), and RS (n = 24, 8%). The ATP effectiveness was 80% (86% in QS, 85% in QR, 74% in R, 62% in RS). The frequency of successful ATP was higher in QFVT: 86 versus 71% (P = 0.002). By logistic regression analysis, a QFVT pattern (OR = 2.3; P = 0.015) remained as an independent predictor of effective ATP. ATP was safer in QFVTs, the frequencies of shock (14% vs 29%; P = 0.002), acceleration (5.1 vs 12.3%; P = 0.02), and syncope (4.6 vs 12.3%; P = 0.01) being lower. CONCLUSIONS: Since ATP is less effective in non-QFVTs, they are less well tolerated. Therefore, the substrate of non-QFVTs may need a specific treatment.

Influence of cycle length variations on antitachycardia pacing effectiveness among ICD patients.

BACKGROUND: Antitachycardia pacing (ATP) fails to terminate 5% to 25% of ventricular tachycardias (VTs) occurring in implantable cardioverter-defibrillator patients. We speculated that small fluctuations in VT cycle length (CL) may be related to the efficacy of subsequent ATP. OBJECTIVE: The purpose of this study was to determine the relationship between the R-R variations of the last 12 R-R intervals before ATP and the efficacy of the first ATP attempt. METHODS: We studied 551 VTs (CL 329±35 ms) occurring in 67 patients. We also analyzed the percentage of variation (P-RR), which was calculated by dividing the mean difference between each R-R interval and the next one by the CL (×100), and the acceleration index (AI), which was calculated by dividing the CL of the first 6 R-R intervals by the CL of the next 6. RESULTS: The effectiveness of the first ATP therapy was 81%, being higher in VTs with AI<1 (85% vs 64%; P<.001). After classifying the events according to the tertiles of P-RR, ATP efficiency was better in higher values of P-RR (VTs with AI<1): 99% (third tertile) vs 85% (second tertile) vs 76% (first tertile), P<.001; and for VTs with AI≥1: 94% vs 68% vs 42% (P<.001). By logistic regression, P-RR (%; odds ratio 2.37; P<.001), and AI<1 (odds ratio 4.17; P<.001) were found to be independent predictors of successful first ATP attempts. CONCLUSION: Small changes in CL increase the effectiveness of ATP significantly. VTs with lower degrees of R-R fluctuations, especially when the pattern is a progressive CL shortening, are infrequently terminated by ATP.

Influence of beta-blocker therapy on antitachycardia pacing effectiveness for monomorphic ventricular tachycardias occurring in implantable cardioverter-defibrillator patients: a dose-dependent effect.

AIMS: To determine, in a non-selected population of 282 implantable cardioverter-defibrillator (ICD) patients with left ventricular dysfunction, the influence of the dose of beta-blockers on antitachycardia pacing (ATP) effectiveness and on the incidence of shock due to monomorphic ventricular tachycardias (VT). METHODS AND RESULTS: We followed 282 ICD patients along 26 +/- 19 months. Antitachycardia pacing and shock programming were standardized. We determined the indexed dose equivalent of beta-blockers (IDE-BB), using metoprolol as a reference, at each VT presentation. The median of IDE-BB was 55 mg/m(2)/day. We analysed 846 VT occurred in 100 patients. The ATP success rate was 84%. Upon classification of the events into three groups (IDE-BB = 0, IDE-BB < 55, and IDE-BB > or = 55), the frequency of effective ATP increased with the IDE-BB: 75 vs. 83 vs. 92% (P < 0.001). According to logistic regression, IDE-BB remained as an independent predictor of effective ATP (P < 0.001) and VT-related shock (P = 0.001). Both the mean ATP effectiveness per patient (67 vs. 80 vs. 91%, P = 0.007) and the mean survival time free of VT-related shock (583 vs. 847 vs. 1158 days, P = 0.019, log-rank test) increased linearly with the dose of beta-blockers. CONCLUSION: Beta-blockers increase the effectiveness of ATP through a dose-dependent effect. As a result, they reduce the incidence of shocks due to VT.

Relationship between the duration of the basal QRS complex and electrical therapies for ventricular tachycardias among ICD patients.

BACKGROUND: In implantable cardioverter-defibrillators (ICD) patients, the duration of the basal QRS complex (QRSd) is not associated with a greater risk of developing ventricular tachyarrhythmias. QRSd could be inversely related to the effectiveness of antitachycardia pacing (ATP) because it may be associated with longer conduction times of the paced-impulses and hence, with a greater propensity to require shocks to terminate ventricular tachycardias (VTs). METHODS: We followed 216 ICD patients (pacing site: right ventricular apex; QRSd 100 remained as an independent predictor of receiving shocks to terminate VTs (P = 0.01). According to Kaplan-Meier analysis, the occurrence of VTs was similar regardless of the QRSd (30% vs 38%; P = 0.2), but the incidence of shock due to VTs was higher in patients with a QRSd > 100 (19% vs 7%; P = 0.01). CONCLUSION: Since QRSd is a negative and independent predictor of effective ATP, ICD patients with QRSd > 100 ms require shocks more frequently to terminate VTs.

Importance of the relationship between sinus cycle length and junctional rhythm cycle length (occured during radiofrequency ablation) in predicting the successful modification of the slow pathway in Atrioventricular Nodal Re-entrant Tachycardias.

BACKGROUND: In atrioventricular nodal re-entrant tachycardias (AVNRT), the achievement of Junctional Rhythms (JR) during Radiofrequency Ablation (RF) is a sensitive but non-specific marker of success. Our aim is to analyze prospectively the predictors of non-inducibility of AVNRT, focusing on the characteristics of the JR. METHODS: We included 75 patients with reproducibly inducible AVNRT. Ablation was performed following an electro-anatomical approach. After each application, the induction protocol was repeated. RESULTS: A total of 341 applications were performed. Although the achievement of >/=1 JR was necessary to obtain the non-inducibility, and the cumulative number of junctional beats (CJB) was higher in effective applications, no CJB cut-off was associated with a success rate higher than 75%. After the observation of a significant correlation between the sinus cycle length (CL) pre-RF and the CL of the JR (JR-CL) (c=0.52; p<0.001), the sinus CL pre-RF/JR-CL ratio (CL-ratio) adequately differentiated the successful vs. unsuccessful applications: 1.41+/-0.23 vs. 1.17+/-0.2 (p<0.001). In a multivariate analysis, a CBJ 11 (p<0.001) and a CL-ratio 1.25 (p<0.001) were found to be the only independent predictors of success. The combination of >/= 11 of CJB with a CL ratio >/= 1.25 achieved non-inducibility in 97% of our patients. CONCLUSION: 1) The specificity of the occurrence of JR as a marker of the successful ablation of AVNRT is increased by the CL-ratio. 2) The achievement of >/= 11 of CJB with a CL ratio >/= 1.25 predicts non-inducibility in almost all patients.

Relationship between QRS duration and prognosis in non-ST-segment elevation acute coronary syndrome.

BACKGROUND: Previous studies have shown that prolonged QRS duration increases the risk of death in patients with heart failure and after an ST-segment elevation acute myocardial infarction. Very little data exist about the prognostic implications of QRS duration in the non-ST-segment elevation acute coronary syndrome (NST-ACS): unstable angina and non-ST elevation acute myocardial infarction (non-STEMI). METHODS: This is a prospective and observational study in which we included 502 patients (age 71+/-10 years, 68% males, 29% diabetes) consecutively admitted for NST-ACS. QRS duration was manually measured from the 12-lead electrocardiogram. Our aim is to assess the relation between the QRS duration on admission (QRSd) and the risk of cardiovascular death (CvD) in the long-term. RESULTS: Mean QRSd was: 93+/-19 ms. After a median follow-up of 450 days, the cumulative incidence of CvD was: 17.8%. QRSd correlated with the incidence of CvD during the follow-up period: c=0.72 (p<0.001). The best cut-off point was 90 ms (sensitivity, specificity and negative predictive value of QRSd>or=90 ms for CvD: 82, 68 and 93%). According to the Kaplan-Meier analysis, QRSd>or=90 ms was associated with an increase in the risk of CvD: 26.6% versus 7.2% (log rank: 28.6; p<0.001). Cumulative incidence of CvD was higher in QRSd>or=90 ms in patients with unstable angina: 15.5% versus 4% (p=0.02), and in those with non-STEMI: 30.5% versus 8.9% (p<0.001). After adjusting for other significant variables (Cox-regression analysis), QRSd>or=90 ms persisted as an independent predictor for overall CvD (Hazard Ratio: 2.62; 95% Confidence Interval: 1.44-4.74; p<0.001). CONCLUSION: In NST-ACS, the QRSd, even in the normal range, has prognostic implications. QRSd>or=90 ms is independently associated with an increased risk of CvD in the long-term.

Short- and long-term prognostic value of the corrected QT interval in the non-ST-elevation acute coronary syndrome.

BACKGROUND AND PURPOSE: Myocardial ischemia prolongs the QTc interval. Very little data exists about its prognostic implications in the non-ST-elevation acute coronary syndromes (NST-ACS). METHODS: This is and observational and prospective study in which we evaluated the prognostic implications of the QTc obtained at admission (AQTc) in the short- and long-term of the NST-ACS. The median of the follow-up was 17 months. RESULTS: AQTc correlated adequately with the incidence of adverse events in the short- and long-term (P < .001), with the best cut-off point in 450 milliseconds. Patients with AQTc > or =450 presented higher frequency of in-hospital death: 8.8% vs 1.2%; P = .001, and MACE (death, recurrent ischemia, or urgent coronary revascularization): 72% vs 25%; P < .001. In a Cox regression analysis, we found 3 independent predictors of cardiovascular death after discharge: AQTc > or =450 (14.7% vs 2.1%; P < .0001), age >65 years and left ventricular ejection fraction <40%. Coronary revascularization reduced the risk of posthospitalary cardiovascular death in AQTc > or =450 milliseconds (5% vs 24%; P < .0001) but had no significant effect in AQTc<450 milliseconds. CONCLUSION: These findings provide a new evidence supporting the prognostic value of the AQTc in predicting unfavorable events in the short- and long-term of the NST-ACS.

[Long-term prognostic value of troponin I in patients admitted to a coronary unit for unstable angina]. / Valor pronóstico de la troponina I en los pacientes ingresados en una unidad coronaria por angina inestable.

INTRODUCTION AND OBJECTIVES: Troponin I (TnI) is a useful marker of myocardial damage for the diagnosis and prognosis of acute coronary syndrome. The purpose of this study was to analyze the long-term prognostic value of the peak TnI concentration obtained within 48 h of admission to the coronary unit for unstable angina. METHODS: The study included 149 consecutive patients. Serial determinations were made of the MB fraction of creatine kinase (CK-MB) and TnI. Patients without CK-MB elevation were classified into two groups depending on the presence of high (n = 58) or normal (n = 91) troponin I values. We prospectively analyzed the clinical and evolutive factors related to the probability of death, new acute coronary event, or coronary revascularization at one-year of follow-up. RESULTS: There were no differences in the clinical characteristics between groups, except that patients in the group with high TnI values were older (69 vs. 64 years, p = 0.01). At one year of follow-up there were no differences in the incidence of new acute coronary events or coronary revascularization procedures; however there was a higher mortality in the group with high TnI (13 vs. 4%; p = 0.01). The independent predictors of mortality were prior myocardial infarction (RR = 3), elevated troponin I (RR = 3.2), left ventricular ejection fraction < 35% (RR = 10), and age > 70 years (RR = 15). CONCLUSIONS: In patients with unstable angina a high troponin I value in the first 48 h of admission was associated with a higher mortality rate at one-year of follow-up.

Valor pronóstico tardío de la troponina I en los pacientes ingresados en una unidad coronaria por angina inestable / Long-term prognostic value of troponin i in patients admitted to a coronary unit for unstable angina

Introducción y objetivos. La troponina I (TnI) es un marcador de daño miocárdico utilizado en la estratificación pronóstica del síndrome coronario agudo. El objetivo del estudio fue analizar el valor pronóstico tardío del nivel máximo de TnI obtenido en las 48 h tras el ingreso en una unidad coronaria por angina inestable. Métodos. Se incluyó a 149 pacientes consecutivos. Se realizaron determinaciones seriadas de la fracción MB de la creatincinasa (CK-MB) y TnI. Los pacientes sin elevación de la CK-MB fueron clasificados en dos grupos, en función de la presencia de TnI elevada (n = 58) o normal (n = 91). Se analizaron prospectivamente los factores clínicos y evolutivos relacionados con la probabilidad de muerte, nuevo episodio agudo coronario o revascularización coronaria tras un año de seguimiento. Resultados. No se observaron diferencias entre los dos grupos en relación con las características clínicas, salvo la edad, que fue mayor en el grupo con TnI elevada (69 frente a 64 años; p = 0,01). Tras un año de seguimiento no se apreciaron diferencias en la incidencia de nuevos acontecimientos coronarios agudos ni en la revascularización; sin embargo, la mortalidad fue mayor en el grupo con TnI elevada (el 13 frente al 4 per cent; p = 0,01).Los predictores independientes de mortalidad fueron el infarto previo (riesgo relativo [RR] = 3), TnI elevada (RR = 3,2), fracción de eyección 70 años (RR = 15).Conclusiones. En la angina inestable, un valor elevado de TnI dentro de las primeras 48 h del ingreso se asocia con un aumento de la mortalidad al año de seguimiento (AU)

[Clinical safety and efficacy of single-chamber atrial pacing in sick sinus syndrome: long-term follow-up]. / Seguridad y eficacia clínica de la estimulación con el modo AAI en la disfunción del nodo sinusal: seguimiento a largo plazo.

INTRODUCTION AND OBJECTIVES: Although atrial pacing is a more physiological mode of stimulation in sinus node dysfunction, the pacing modes most often are used DDD and VVI. The aim of our study was to demonstrate that AAI/AAIR pacing is effective and safe by analyzing the complications and mortality of this pacing mode in a long-term follow-up study. PATIENTS AND METHOD: Between 1982 and 2000 definitive AAI-mode pacemakers were implanted for sinus node dysfunction in mode AAI in 160 patients. We analyzed the clinical characteristics, evolution, and complications of the AAI pacing mode during a follow-up of 5.4 4.5 years. RESULTS: The sample was made up of 104 women and 56 men with an average age of 72 12 years. During follow-up, it was necessary to change the pacing mode for symptomatic bradycardia in 11 patients (annual incidence 1.2%), which was caused by second or third-degree atrioventricular block in 7 patients (annual incidence 0.8%), and chronic atrial fibrillation with bradycardia in 4 patients (annual incidence 0.4%). During follow-up, atrial arrhythmias occurred in 32 patients (annual incidence 3.7%), stroke in 4 patients (annual incidence 0.4%), and 27 patients (annual incidence 3.1%) died. CONCLUSIONS: The AAI/AAIR pacing mode was safe and effective in sinus node dysfunction, with a low percentage of pacing changes required for progression to atrioventricular block, low incidence of atrial arrhythmias, stroke and low mortality during long term follow-up.

Seguridad y eficacia clínica de la estimulación con el modo AAI en la disfunción del nodo sinusal: seguimiento a largo plazo / Clinical safety and efficacy of single-chamber atrial pacing in sick sinus syndrome: long-term follow-up

Introducción y objetivos. Aunque el modo de estimulación auricular es el más fisiológico en la disfunción del nodo sinusal, la estimulación en modo DDD y VVI son las empleadas mayoritariamente. El objetivo de nuestro estudio es demostrar que una estimulación en modo AAI/AAIR es eficaz y segura; para ello hemos analizado las complicaciones y la mortalidad de este modo de estimulación en una evolución a largo plazo. Pacientes y método. Entre 1982 y 2000 se implantó un marcapasos definitivo por DNS sintomática en modo AAI a 160 pacientes. Se ha realizado un análisis de las características clínicas, de la evolución y complicaciones del modo de estimulación AAI durante un seguimiento medio de 5,4 ñ 4,5 años. Resultados. La muestra estudiada está compuesta de 104 mujeres y 56 varones, con una edad media de 72 ñ 12 años. En el seguimiento fue preciso cambiar el modo de estimulación por bradicardia sintomática en 11 pacientes (1,2 por ciento anual), bloqueo auriculoventricular de segundo a tercer grado en 7 pacientes (0,8 por ciento anual) y fibrilación auricular crónica con frecuencias lentas en 4 enfermos (0,4 por ciento anual). Se presentaron arritmias auriculares en 32 pacientes (3,7 por ciento anual), accidentes cerebrovasculares (ACV) en 4 pacientes (0,4 por ciento anual) y 27 enfermos (3,1 por ciento anual) fallecieron durante el seguimiento. Conclusiones. El modo de estimulación AAI en la disfunción del nodo sinusal es seguro y eficaz, con un bajo porcentaje de cambios de estimulación por progresión a bloqueo auriculoventricular, baja incidencia de arritmias auriculares, ACV y una baja mortalidad durante el seguimiento a largo plazo (AU)

Taquicardia ventricular y hemocromatosis cardíaca / Ventricular Tachycardia and Cardiac Hemochromatosis

La hemocromatosis está caracterizada por un excesivo depósito de hierro en una variedad de tejidos. La afección cardíaca sucede en un tercio de los pacientes con hemocromatosis y se produce como consecuencia de una acumulación de ferritina en el músculo cardíaco que induce por un lado una alteración en la función ventricular sistólica y diastólica y por otro un sustrato arritmogénico. Las manifestaciones clínicas pueden estar indistintamente relacionadas con taquiarritmias auriculares, ventriculares, bloqueos aurículoventriculares y/o con insuficiencia cardíaca congestiva, siendo más frecuentes las primeras. Presentamos el caso de una paciente con hemocromatosis secundaria a transfusiones repetidas por anemia sideroblástica con afección cardíaca y cuyas primeras manifestaciones cardíacas fueron taquiarritmias auriculares recurrentes y taquicardia ventricular sostenida sincopal, por lo que se implantó un desfibrilador automático (AU)

Perforación de un electrodo epicárdico: una evolución atípica / Perforating epicardial lead: atypical evolution

La endocarditis sobre un electrodo de marcapasos es una complicación rara, cuyo diagnóstico se realiza por la presencia de verrugas en ecocardiografía y hemocultivos positivos, siendo su tratamiento mixto -médico y quirúrgico- pues el tratamiento médico aislado raramente tiene éxito y el electrodo debe ser extraído. Presentamos el caso de una endocarditis recurrente de varios años de evolución en el que no fue posible la extracción del electrodo debido a las características especiales del caso (electrodo epicárdico perforante en aurícula derecha) (AU)