Smoking-attributable mortality by sex in the 27 Brazilian federal units: 2019.

OBJECTIVES: The aim of this study was to estimate smoking-attributable mortality (SAM) in the population aged 35 years and over in Brazil's 27 federal units by sex, in 2019. STUDY DESIGN: This is an attributable mortality analysis. METHODS: We applied a method dependent on the prevalence of smoking, based on the population attributable fractions. Data on mortality due to causes causally related to smoking were derived from Brazil's Death Registry, data on prevalence of smoking from a survey conducted in Brazil in 2019, and data on relative risks from five US cohorts. Crude and age-adjusted SAM rates were calculated by sex. Estimates of SAM were calculated by specific causes of death and major mortality groups for each federal unit by sex. RESULTS: In 2019, smoking caused 480 deaths per day in Brazil. Although the SAM varied among the federal units, the pattern is not clear, with the greatest difference being between Rio Grande do Sul (crude rate: 248.8/100,000 inhabitants) and Amazonas (106.0/100,000). When the rates were adjusted by age, the greatest differences were observed between Acre (271.1/100,000) and Distrito Federal (131.1/100,000). SAM was higher in males; however, while the main specific cause of SAM in men was ischemic heart disease, in women it was chronic obstructive pulmonary disease. The major mortality group having the greatest impact on SAM across all federal units was the cardiometabolic diseases. CONCLUSIONS: The variability in the burden of SAM in the different regions of Brazil reaffirms the need for SAM data disaggregated at the geographic level.

Antimicrobial effect of Moringa oleifera seed powder against Vibrio cholerae isolated from the rearing water of shrimp (Penaeus vannamei) postlarvae.

Shrimp farming has experienced rising costs as a result of disease outbreaks associated with Vibrio spp. Suitable strategies for disease prevention and control are therefore urgently needed. This study aimed to evaluate the antimicrobial effect of Moringa oleifera seed powder against Vibrio cholerae in the rearing water of Pacific white shrimp (Penaeus vannamei) postlarvae. In vitro assays included the determination of minimum inhibitory concentration (MIC) of M. oleifera seed powder against V. cholerae, whereas in vivo assays included the effect of M. oleifera seed powder on bacterial load and water quality parameters in the rearing tanks, as well as its effect on shrimp postlarvae survival. M. oleifera seed powder inhibited the growth of V. cholerae with MIC values of 62·5 µg ml-1 . Moreover, seawater pH of treated tanks (8·66) was significantly lower (P < 0·01) than pH of the control tanks (9·02), whereas the visibility of treated tanks (37·08 cm) was significantly higher (P < 0·01) as compared to control tanks (35·37 cm). Likewise, V. cholerae load was significantly reduced (P < 0·01) from 4·7 × 104 to 3·1 × 103  CFU per ml in tanks treated with M. oleifera seed powder. Altogether, this study demonstrates the antimicrobial activity of M. oleifera against V. cholerae in shrimp culture.

Canine rabies elimination: governance principles.

Rabies is still one of the deadliest diseases known to exist in the 21st century, and yet it remains irresponsibly neglected and underestimated. In light of this, this paper discusses the principles of governance as they relate to rabies control, using examples of global intersectoral coordination programmes for the control of canine rabies and for the elimination of human rabies transmitted by dogs. The first of these programmes was the Meeting of Rabies Program Directors of the Americas (REDIPRA), which has served as a model of intersectoral success for rabies elimination in other regions. Examples of intersectoral cooperation on several continents, mainly between the health and agriculture sectors, are detailed to discuss various methods of achieving better technical cooperation. These cooperation programmes follow the 'coalition model' set by REDIPRA. They bring together various actors, such as governments, non-governmental organisations, the private sector, the science and research community, international cooperation agencies and donors, under a common umbrella for advocacy and for the implementation of local projects for the elimination of human rabies transmitted by dogs. Networking is the main intersectoral governance mechanism presented in this review.

Bien qu'elle soit connue pour être l'une des maladies faisant le plus de victimes au xxie siècle, la rage demeure fortement négligée et sous-estimée, traduisant un déficit de responsabilité en la matière. À la lumière de cet état de fait, les auteurs examinent les principes de gouvernance applicables à la lutte contre la rage, en prenant pour exemples les programmes mondiaux destinés à assurer la coordination intersectorielle de la lutte contre la rage canine et de l'élimination de la rage humaine transmise par les chiens. Le premier des programmes examinés est celui mis en oeuvre par les Réunions des Directeurs des Programmes nationaux de contrôle de la rage en Amérique latine (REDIPRA), qui a servi de modèle dans d'autres régions du monde en tant qu'exemple de coopération intersectorielle réussie pour l'élimination de la rage. Les auteurs examinent en détail quelques exemples de coopération intersectorielle dans différents continents et portant pour la plupart sur les secteurs de la santé et de l'agriculture, ce qui les conduit à mettre en avant les méthodes permettant d'améliorer la qualité de la coopération technique. Ces programmes de coopération s'inspirent du « modèle de coalition ¼ inauguré par les REDIPRA. Ils réunissent plusieurs acteurs tels que les gouvernements, les organisations non gouvernementales, le secteur privé, la communauté des chercheurs et des scientifiques, les agences de coopération internationale et les donateurs, autour d'un objectif commun axé sur la promotion et la mise en oeuvre des projets locaux d'élimination de la rage humaine transmise par les chiens. Le travail en réseaux est le principal mécanisme de gouvernance intersectorielle présenté dans cette analyse.

La rabia es todavía una de las enfermedades más mortíferas que se conocen y aún subsisten en el siglo XXI, pese a lo cual sigue estando, de forma harto irresponsable, desatendida y subestimada. Ante tal realidad, los autores exponen los principios de la gobernanza en relación con la lucha antirrábica, ofreciendo ejemplos de programas de coordinación intersectorial a escala mundial para combatir la rabia canina y eliminar la rabia humana transmitida por perros. El primero de tales programas fue la «Reunión de directores de programas contra la rabia de las Américas¼ (REDIPRA), que después ha servido de modelo de labor intersectorial eficaz para la eliminación de la rabia en otras regiones. Tras describir en detalle ejemplos de cooperación intersectorial en varios continentes, básicamente entre los sectores de la agricultura y la salud, los autores examinan varios métodos para dotar de más eficacia a la cooperación técnica. Estos programas de cooperación siguen el «modelo de coalición¼ establecido por la REDIPRA: se trata de federar a distintos interlocutores (gobiernos, organizaciones no gubernamentales, entidades del sector privado, círculos científicos y de investigación, organismos de cooperación internacional, donantes, etc.) en torno a un designio común de sensibilización y aplicación de proyectos locales para eliminar la rabia humana transmitida por perros. El trabajo en red es el principal mecanismo de gobernanza intersectorial que presentan los autores en estas líneas.

Arthroscopic rotator cuff repair using a single or double row technique: A meta-analysis of randomized clinical trial. / Reparación artroscópica del manguito rotador mediante una técnica de hilera simple o doble hilera: un metaanálisis de los ensayos clínicos aleatorizados.

PURPOSE: To compare the double row technique versus the single row technique for arthroscopic rotator cuff repair, in order to assess whether there are clinical differences. METHODS: Systematic review of randomized clinical trials comparing the clinical results of the double-row technique versus the single-row technique in arthroscopic rotator cuff repair. Demographic, clinical, and surgical variables were analyzed, including functional scores, tendon healing rate, and re-tear rate. RESULTS: Thirteen randomized clinical trials were selected. 437 patients in the single row group (50.7%) and 424 patients in the double row group (49.3%) were analyzed. No significant differences were found between the two groups in terms of age (P=.84), sex (P=.23) and loss to follow-up (P=.52). Significant differences were found for the better results of the double row technique at the UCLA level (P=.01). No significant differences were found on the Constant-Murley scale (P=.87) or on the ASES scale (P=.56). Similarly, there was a higher healing rate (P=.006) and less risk of rotator cuff re-tears with the double row technique (P=.006). CONCLUSIONS: In rotator cuff repair, the double row technique was found to be superior to the single row technique in terms of better UCLA score, better tendon healing rate, and lower re-tear rate. No clinically significant differences were found on the Constant-Murley scale or on the ASES scale.

Frequency of fatal and non-fatal overdoses and response to grief and loss among people who inject drugs: An unexplored dimension of the opioid overdose crisis.

BACKGROUND: We investigated the relationship between overdose events and grief and loss responses among people who inject drugs. METHODS: We conducted a cross-sectional, tablet-based survey with a convenience sample of people who inject drugs (n = 249) from four community-based harm reduction programs in Toronto in 2019. We examined the association between frequency and types of overdose events (own, witnessed, death of significant person) in the last 6 months with grief and loss responses, identified using latent class analysis. RESULTS: Among respondents, 70 (48.6 %) reported 2 or more personal overdoses, 173 (79.5 %) witnessed 2 or more overdoses, and 69 (41.4 %) experienced overdose deaths of 2 or more significant persons in the last 6 months. We identified 2 latent classes with probability of membership of 38.6 % (95 % confidence interval [CI]=31.0, 46.7) for medium/low intensity of responses to grief/loss and 61.4 % (95 % CI= 53.3, 69.0) for severe responses to grief/loss. In adjusted Poisson regression models with robust standard error estimators, severe responses to grief/loss were associated with exposure to two or more own overdoses (prevalence ratio [PR] = 1.44; 95 % CI=1.12, 1.84, p-value=0.004), and having witnessed one (PR=2.09; 95 % CI=1.05, 4.15, p-value=0.04) or witnessed two or more overdoses (PR=2.25; 95 % CI=1.24, 4.09, p-value=0.008). Severe grief/loss responses were also more common in individuals exposed to all three types of overdose events (PR=2.42; 95 % CI=1.08, 5.41, p-value=0.03). CONCLUSIONS: Cumulative overdose events were associated with severe responses to grief and loss. Bereavement interventions should consider the complex nature of grief and loss following overdoses.

Analgesic activity of Heliopsis longipes and its effect on the nervous system.

Heliopsis longipes S.F. Blake (Asteraceae: Heliantheae) (chilcuague) is used in Mexican traditional medicine against parasites and to alleviate tooth and muscle pains. Its biocide effect has already been experimentally demonstrated; however, its analgesic action and its action on the nervous system (NS) have not been investigated yet. The objectives of this study were to evaluate the analgesic action of affinin and the H. longipes root ethanol extract, as well as their effects on the NS using an animal model. The ethanol extract was obtained by maceration, and affinin was purified from it through chromatographic techniques. Chemical and thermal analgesia were used to assess their analgesic proprieties. Irwin's test was used to evaluate their stimulating or depressing effects. The ethanol extract and affinin displayed analgesic action similar to ketorolac and stimulating effect comparable to caffeine on the nervous system of adult mice.

Nevertheless, She Resisted - Role of the Environment on Listeria monocytogenes Sensitivity to Nisin Treatment in a Laboratory Cheese Model.

The growth of Listeria monocytogenes on refrigerated, ready-to-eat food products is a major health and economic concern. The natural antimicrobial nisin targets the bacterial cell wall and can be used to inhibit L. monocytogenes growth on cheese. Cell wall composition and structure, and therefore the efficacy of cell wall acting control strategies, can be severely affected by environmental and stress conditions. The goal of this study was to determine the effect of a range of pH and temperatures on the efficacy of nisin against several strains of L. monocytogenes in a lab-scale, cheese model. Cheese was made with or without the addition of nisin at different pH and then inoculated with L. monocytogenes; L. monocytogenes numbers were quantified after 1, 7, and 14 days of incubation at 6, 14, or 22°C. While our data show that nisin treatment is able to reduce L. monocytogenes numbers, at least initially, growth of this pathogen can occur even in the presence of nisin, especially when cheese is stored at higher temperatures. Several environmental factors were found to affect nisin efficacy against L. monocytogenes. For example, nisin is more effective when cheese is stored at lower temperatures. Nisin is also more effective when cheese is made at higher pH (6 and 6.5), compared to cheese made at pH 5.5, and this effect is at least partially due to the activity of cell envelope modification genes dltA and mprF. Serotype was also found to affect nisin efficacy against L. monocytogenes; serotype 4b strains showed lower susceptibility to nisin treatment compared to serotype 1/2 strains. Overall, our results highlight the importance of considering environmental conditions specific to a food matrix when developing and applying nisin-based intervention strategies against L. monocytogenes.

Metal-ligand pair anisotropy in a series of mononuclear Er-COT complexes.

Synthetic control of the crystal field has elevated lanthanides to the forefront of single-molecule magnet (SMM) research, yet the resultant strong, predictable single-ion anisotropy has thus far not translated into equally impressive molecule-based magnets of higher dimensionality. This roadblock arises from the dual demands made of the crystal field: generate anisotropy and facilitate magnetic coupling. Here we demonstrate that particular metal-ligand pairs can dominate the single-ion electronic structure so fully that the remaining coordination sphere plays a minimal role in the magnitude and orientation of the magnetic anisotropy. This Metal-Ligand Pair Anisotropy (MLPA) effectively separates the crystal field into discrete components dedicated to anisotropy and magnetic coupling. To demonstrate an MLPA building unit, we synthesized four new mononuclear complexes that challenge the electronic structure of the iconic lanthanocene ([Ln(COT)2]+; COT2- = cyclooctatetraene dianion) complex which is known to generate strong anisotropy with Ln = Er3+. Variation in symmetry and coordination strength for Er(COT)I(THF)2 (THF = tetrahydrofuran) (1), Er(COT)I(Py)2 (Py = pyridine) (2), Er(COT)I(MeCN)2 (MeCN = acetonitrile) (3), and Er(COT)(Tp*) (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate) (4) shows that the Er-COT unit stabilizes anisotropy despite deliberate de-optimization. All four half-sandwich complexes display SMM behavior with effective energy barriers of U eff = 95.6(9), 102.9(3.1), 107.1(1.3), and 133.6(2.2) cm-1 for 1-4 by a multi-relaxation-process fitting. More importantly, the basic state splittings remain intact and the anisotropy axes are within several degrees of normal to the COT2- ring according to complete active space self-consistent field (CASSCF) calculations. Further investigation of the MLPA conceptual framework is warranted as it can provide building units with well-defined magnetic orientation and strength. We envision that the through-barrier processes observed herein, such as quantum tunneling, can be mitigated by formation of larger clusters and molecule-based materials.

Identification and characterization of a nodH ortholog from the alfalfa-nodulating Or191-like rhizobia.

Nodulation of Medicago sativa (alfalfa) is known to be restricted to Sinorhizobium meliloti and a few other rhizobia that include the poorly characterized isolates related to Rhizobium sp. strain Or191. Distinctive features of the symbiosis between alfalfa and S. meliloti are the marked specificity from the plant to the bacteria and the strict requirement for the presence of sulfated lipochitooligosaccharides (Nod factors [NFs]) at its reducing end. Here, we present evidence of the presence of a functional nodH-encoded NF sulfotransferase in the Or191-like rhizobia. The nodH gene, present in single copy, maps to a high molecular weight megaplasmid. As in S. meliloti, a nodF homolog was identified immediately upstream of nodH that was transcribed in the opposite direction (local synteny). This novel nodH ortholog was cloned and shown to restore both NF sulfation and the Nif+Fix+ phenotypes when introduced into an S. meliloti nodH mutant. Unexpectedly, however, nodH disruption in the Or191-like bacteria did not abolish their ability to nodulate alfalfa, resulting instead in a severely delayed nodulation. In agreement with evidence from other authors, the nodH sequence analysis strongly supports the idea that the Or191-like rhizobia most likely represent a genetic mosaic resulting from the horizontal transfer of symbiotic genes from a sinorhizobial megaplasmid to a not yet clearly identified ancestor.

Ferromagnetic coupling in a chloride-bridged erbium single-molecule magnet.

We present the first ferromagnetically-coupled Er3+ complex with linked, high-anisotropy Er-COT (COT2- = cyclooctatetraene dianion) subunits. The dinuclear complex, [Er(µ2-Cl)(COT)(THF)]2, demonstrates single-molecule magnetism with a single, zero-field magnetization relaxation barrier of Ueff = 113 cm-1. This system offers evidence that anisotropy can be preserved in the presence of ferromagnetic linking of the Er-COT subunits, providing a rational means to build strong molecular magnets of tunable dimensionality.

Importance of abortive shock capability with electrogram storage in cardioverter-defibrillator devices.

OBJECTIVES: This study evaluates the ability of a third-generation cardioverter-defibrillator to abort energy delivery and the importance of electrogram storage in analyzing the aborted events. BACKGROUND: In the Cadence Tiered Therapy Defibrillator, when a tachycardia satisfies detection criteria for cardioversion or defibrillation therapy, high voltage capacitors begin charging. The Cadence defibrillator continues monitoring the rhythm during charging and if the rate decreases to below the rate triggering therapy, charging is terminated. This event is registered as an aborted shock. The defibrillator also has the ability to store intracardiac electrogram recordings of the electrical events that precipitate device therapy or aborted shocks. METHODS: During a mean follow-up interval of 10 +/- 7 months, 55 aborted events were registered by the Cadence defibrillator in 18 of the 49 patients who received it. Thirty-two stored ventricular electrograms of events leading to aborted shocks were available for analysis in 15 patients. RESULTS: Intracardiac electrogram recordings demonstrated the probable electrical events leading to these aborted shocks included nonsustained ventricular tachycardia (n = 10), nonsustained rapid polymorphic ventricular tachycardia/ventricular fibrillation (n = 2), atrial fibrillation (n = 5), supraventricular tachycardia (n = 2) and electrical noise (n = 13). Eleven patients had a therapeutic intervention initiated as a consequence of the diagnostic information provided by analysis of intracardiac electrogram recordings. Four of the 15 patients had no changes made. During a follow-up period of 9 +/- 5 months after therapy was altered, no patient had subsequent aborted shocks. Five patients have had seven appropriate shocks for sustained ventricular tachycardias. CONCLUSIONS: The ability of Cadence defibrillator to continue tachycardia sensing during capacitor charging and to abort shock therapy for self-terminating events prevented unnecessary shocks in 18 (37%) of the 49 patients. Intracardiac electrogram recordings were critical for instituting appropriate therapy that may have prevented unnecessary device charging and inappropriate discharges.

Usefulness of electrophysiologic study to determine the clinical tolerance of arrhythmia recurrences during amiodarone therapy.

The relation of clinical and electrophysiologic variables to outcome was evaluated in 121 patients treated with amiodarone for sustained ventricular tachyarrhythmias. Electrophysiologic study was performed in all patients a mean of 14 days after beginning amiodarone therapy. Forty-six patients who were given oral amiodarone therapy experienced arrhythmia recurrence. Multivariate analysis was performed using 16 clinical and electrophysiologic variables to determine which factors were associated with 1) arrhythmia recurrence and 2) a poorly tolerated arrhythmia recurrence (that is, cardiac arrest or sudden cardiac death) during oral amiodarone therapy. No variable predicted arrhythmia recurrence. Five variables correlated significantly with a poorly tolerated arrhythmia recurrence. Hemodynamic stability of the arrhythmia induced on electrophysiologic testing during amiodarone therapy had the best predictive value (p less than 0.001). Younger age, lower ejection fraction, a poorly tolerated rhythm at clinical presentation and absence of left ventricular aneurysm were also associated with a poorly tolerated arrhythmia recurrence. Only 3 of 57 patients who had a well tolerated arrhythmia induced on electrophysiologic testing during amiodarone therapy had recurrence of a poorly tolerated arrhythmia versus 19 of 47 who had hemodynamically unstable arrhythmias induced during amiodarone therapy (p less than 0.001). Thus, electrophysiologic testing during amiodarone therapy appears useful in identifying patients who are prone to have catastrophic arrhythmia recurrences and could allow for the institution of additional or alternative modes of therapy.

Unique sensing errors in third-generation implantable cardioverter-defibrillators.

OBJECTIVES: Third-generation cardioverter-defibrillators appear to be susceptible to unique sensing errors. This study was performed to determine the incidence and types of sensing errors in combination therapy implantable devices. BACKGROUND: One of the advantages offered by third-generation implantable cardioverter-defibrillators is the combination of bradycardia and antitachycardia pacing and cardioversion-defibrillation capabilities in a single device. The potential for unique sensing errors, those caused by the conflicts presented by combining bradycardia and tachycardia sensing and therapy algorithms in the same device, has not been previously addressed. METHODS: To determine the incidence of important sensing errors, 61 patients with a combination therapy device (Cadence [Ventritex] and PCD [Medtronic]) were studied for a 25-month period. In addition to surface electrocardiographic recordings during implantation and routine device testing, real-time and stored electrograms recorded from the rate-sensing leads (Cadence) and real-time marker channel recordings (PCD) were reviewed to diagnose sensing errors that resulted in symptoms, device inefficacy or delivery of inappropriate therapy. After recognition, specific reprogramming steps were performed in an attempt to avoid recurrent sensing errors. RESULTS: A total of 13 sensing errors were diagnosed in 12 patients (19.7%); the incidence was similar in both devices. Five distinct categories of sensing errors were identified. After device reprogramming, only one recurrent error occurred in 98 patient-months of follow-up. CONCLUSIONS: Important sensing errors occur in approximately 20% of patients with third-generation combination therapy cardioverter-defibrillators. Prompt diagnosis of sensing errors can lead to specific reprogramming steps to avoid recurrent errors.

Peroxidase activity of a TSA-like antioxidant protein from a pathogenic amoeba.

The 29 kDa surface protein of Entamoeba histolytica is an abundant antigenic protein expressed by pathogenic strains of this organism. The protein is a member of a widely-dispersed group of homologues which includes at least two cysteinyl peroxidases, Salmonella typhimurium alkyl hydroperoxidase C-22 protein (AhpC) and Saccharomyces cerevisiae thiol-specific antioxidant protein (TSA). Here, for the first time in a pathogenic eukaryote, we have demonstrated that the amoebic protein also possesses peroxidatic and antioxidant activities in the presence of reductants such as dithiothreitol or thioredoxin reductase plus thioredoxin. Although the S. typhimurium AhpF flavoprotein was not an effective reductant of the amoebic TSA protein, one inhibitory monoclonal antibody directed toward amoebic TSA was also partially inhibitory toward reduced but not oxidized bacterial AhpC. These antioxidant proteins are likely to be important not only in general cell protection, but also in the promotion of infection and invasion by these pathogenic organisms through protection against oxidative attack by activated host phagocytic cells.

Relationship of steady-state serum concentrations of amiodarone and desethylamiodarone to therapeutic efficacy and adverse effects.

The relationship of steady-state serum levels of amiodarone and its major metabolite, desethylamiodarone, to therapeutic and toxic effects was evaluated in 111 patients treated for supraventricular and ventricular arrhythmias. All patients were treated for more than two months (mean 10 +/- 7), and repeated serum levels determined at least two months apart were within 0.5 mg/liter of each other. Effective control of arrhythmias during steady-state therapy was achieved in 91 patients (82 percent of the study populations); recurrent arrhythmias or sudden death did not correlate with levels. An adverse drug effect necessitating cessation of therapy and/or concomitant medical therapy for the adverse effect occurred in 12 patients (11 percent); an additional 33 patients (30 percent) had an adverse effect that did not require change in therapy. The mean serum concentrations of amiodarone and desethylamiodarone associated with adverse drug effects were higher (2.6 +/- 1.2 mg/liter and 2.0 +/- 0.8 mg/liter) than those in patients without adverse effects (2.1 +/- 1.0 mg/liter and 1.5 +/- 0.7 mg/liter), p less than 0.05. An amiodarone serum concentration of 2.5 mg/liter or more had a positive predictive value of 76 percent for identifying patients with an adverse effect. The level of desethyl metabolite of amiodarone correlated directly with the serum amiodarone concentration (r = 0.82). Measurement of desethylamiodarone did not increase the sensitivity or specificity of the amiodarone level alone in the identification of patients at risk for adverse drug effects.

Symptoms and electrocardiographically documented rhythm preceding spontaneous shocks in patients with implantable cardioverter-defibrillator.

During a follow-up of 24 +/- 20 months after treatment with an implantable cardioverter-defibrillator (ICD), 101 of 241 patients (42%) received > or = 1 spontaneous ICD shocks with documentation of the rhythm leading to shock by Holter or telemetry monitoring or stored electrograms by the device. Sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) was documented in 67 of the 101 patients (66%) with electrocardiographically documented shocks, nonsustained VT in 4 patients (4%), supraventricular tachyarrhythmias in 41 patients (41%), and normal sinus or pacemaker rhythm in 10 patients (10%). No, mild (palpitations and/or mild dizziness) and severe symptoms (presyncope/syncope) preceded spontaneous ICD shocks in 20 (30%), 33 (49%) and 27 (42%) of the 67 patients, respectively, with electrocardiographically documented VT or VF, and in 23 (56%), 16 (39%) and 1 (2%) of the 41 patients, respectively, with electrocardiographically documented supraventricular tachyarrhythmias. Three of the 4 patients with nonsustained VT had mild symptoms, and 1 patient with nonsustained VT had presyncope. None of the 10 patients with spurious discharges during normal sinus or pacemaker rhythm had symptoms preceding the ICD shocks. It is concluded that (1) most patients with either electrocardiographically documented VT/VF or a non-VT/VF rhythm preceding spontaneous ICD shocks have no or mild symptoms preceding the shock, and (2) severe symptoms preceding ICD shocks suggest sustained VT or VF as the underlying rhythm, although severe symptoms rarely occur in patients with supraventricular tachyarrhythmias or nonsustained VT.

Hazards of intravenous verapamil for sustained ventricular tachycardia.

In 11 of 25 patients (44%) with sustained ventricular tachycardia (VT) who received intravenous verapamil (5 to 10 mg), acute severe hypotension or loss of consciousness developed, necessitating immediate cardioversion. Comparison of these 11 patients with the 14 who did not have adverse effects after verapamil revealed no significant difference in age, heart disease, ejection fraction, blood pressure before verapamil administration, other oral or intravenous drugs use, verapamil dose or VT characteristics (rate and morphologic pattern). Although most patients with severe adverse effects after verapamil had prior myocardial infarction, deterioration also occurred in patients without coronary disease and in patients with a normal left ventricular ejection fraction. VT terminated after verapamil infusion in 6 patients. No single electrocardiographic morphologic pattern characterized these patients. A control group of 25 patients presenting with hemodynamically stable VT who received other antiarrhythmic agents was examined. Hypotension developed in only 1 patient during acute therapy and did not require emergency cardioversion. Thus, although verapamil may terminate VT, severe adverse effects occur much more often. Use of verapamil to differentiate supraventricular tachycardia with aberrant conduction from ventricular tachycardia is hazardous.

Relation of the intraoperative defibrillation threshold to successful postoperative defibrillation with an automatic implantable cardioverter defibrillator.

To determine the relation between the intraoperative defibrillation threshold and successful postoperative termination of induced ventricular fibrillation (VF) with the automatic implantable cardioverter defibrillator (AICD), 33 patients who underwent AICD implantation were studied. The defibrillation threshold, determined after at least 10 seconds of VF, was 5 J in 2, 10 J in 6, 15 J in 10, 20 J in 10 and 25 J in 5 patients. The AICD energy rating on the first discharge was 28 +/- 1.8 J. Defibrillation of induced VF was demonstrated postoperatively in 29 of 33 (88%) patients. The AICD terminated VF postoperatively in all 18 patients with a defibrillation threshold less than or equal to 15 J. Only 11 of the 15 (73%) patients with a defibrillation threshold greater than or equal to 20 J (p less than 0.04) had VF terminated postoperatively. In all 4 patients in whom the AICD failed to terminate induced VF, the energy difference between the AICD rating and the defibrillation threshold was less than or equal to 10 J. Among the 14 patients with a difference of less than or equal to 10 J between the AICD energy rating and the defibrillation threshold, there were no significant differences between the 4 patients with and the 10 without successful VF termination with respect to the duration of VF induced postoperatively or the AICD lead system. In summary, failure to terminate VF with the AICD is not uncommon (27%) when the defibrillation threshold approaches the energy delivering capacity of the AICD.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic factors in nonsustained ventricular tachycardia.

Electrophysiologic studies were performed in 83 consecutive patients with spontaneous nonsustained ventricular tachycardia (VT). VT was inducible in 52 patients (nonsustained VT only in 37 patients, nonsustained and sustained VT in 13 and sustained VT only in 2). During a follow-up of 3 to 111 months (mean 33), 10 patients died suddenly, 5 with coronary artery disease (CAD) and 5 with dilated cardiomyopathy. All patients with sudden death had an ejection fraction less than or equal to 0.40. Sudden death occurred in 4 of 15 patients with inducible sustained VT, 2 of 37 patients with only nonsustained VT and 4 of 31 patients without inducible VT. One patient with dilated cardiomyopathy and VT inducible only by isoproterenol died suddenly. Three of 5 patients with CAD who had sudden death had had inducible sustained VT, but 3 of 5 patients with cardiomyopathy who had sudden death had no inducible VT. Multivariate analysis revealed that patients with inducible sustained VT or an ejection fraction less than or equal to 0.40 had a 3-fold increased risk of sudden death, and patients with both factors had a 7-fold increased risk of sudden death. This study demonstrates that patients with nonsustained VT with an ejection fraction greater than 0.40 have an uncomplicated course; however, noninducibility does not predict such a course, particularly in patients with cardiomyopathy. The most powerful predictor of risk for sudden cardiac death is a left ventricular ejection fraction less than or equal to 0.40, but the presence of inducible sustained VT is an independent risk factor for sudden death.