Aortic plaques in patients with atrial fibrillation: an often-forgotten risk factor for thromboembolism

Background

CHA2DS2-VASc risk score is the main determinant for maintaining anticoagulation after atrial fibrillation (AF) ablation, irrespective of the procedure outcome. The presence of aortic plaques is included in the score, but isn't regularly assessed previously to AF ablation. This way, risk factors for coronary artery disease (CAD) other than arterial hypertension and diabetes mellitus may influence stroke risk in patients with AF, albeit not being included in the CHA2DS2-VASc score.

Purpose

We sought to evaluate the prevalence of aortic plaques diagnosed during transesophageal echocardiography (TOE) in patients submitted to AF ablation and to assess its determinants and clinical impact on the CHA2DS2-VASc score.

Methods

Retrospective study of patients submitted to AF ablation that performed TOE prior to the procedure, with assessment of aortic plaques. CHA2DS2-VASc risk score was evaluated in the pre-ablation patient evaluation and reassessed after TOE. Demographic, clinical and echocardiographic data, including cardiovascular risk factors, were analyzed. We assessed AF recurrence rate, cerebrovascular events and death during follow-up.

Results

120 patients were submitted to TOE prior to AF ablation from November 2015 to December 2020, mean age 66.6 (±9.55) years, 48% male. In 30 (25%) patients aortic plaques were identified in TOE. Mean CHA2DS2-VASc was 2.2 (±1.47) in pre-ablation evaluation and 2.5 (±1.69) post-TOE, increasing in all patients with aortic plaques and prompting beginning of oral anticoagulation in 5 patients. AF was paroxysmal in 74% and persistent in 26% of patients, mean duration of 6.28 (±3.76) years. Arterial hypertension was present in 79 (66%) of patients, type 2 diabetes mellitus in 24 (20%) and dyslipidemia in 67 (56%). 17 (14%) patients had a prior stroke. During a mean follow-up of 30 (±18.3) months, 32 (27%) patients had AF recurrence and 10 (8%) were submitted to redo procedures. 107 (89%) patients remained under oral anticoagulation, stroke occurred in 1 patient and 2 patients died.

In univariate analysis, age, type 2 diabetes mellitus and dyslipidemia predicted an increase in CHA2DS2-VASc score after TOE (respectively, OR 1.113, 95% CI 1.041–1.190, p-value 0.002; OR 2.907, 95% CI 1.145–7.379, p-value 0.025; and OR 2.442, 95% CI 1.016–5.868, p-value 0.046).

In multivariate analysis, age is the only independent predictor of increased CHA2DS2-VASc score after TOE (OR 1.095, 95% CI 1.013–1.185, p-value 0.023). No risk factor for CAD was independently associated with the presence of aortic plaques (Table 1).

Conclusion

In this population, single CAD risk factors were not independent predictors of aortic plaques. If TOE had not been performed prior to AF ablation, 25% of patients would have had an underestimated CHA2DS2-VASc score and would be off anticoagulation after the procedure, unprotected from thromboembolic events.

Funding Acknowledgement

Type of funding sources: None. Table 1

Predictors of patient and system delay for primary percutaneous coronary intervention

Background

The delay times of the patient and the system for primary percutaneous coronary intervention (p-PCI) have a determining impact on the prognosis of patients with acute myocardial infarction with ST segment elevation (STEMI).

Purpose

To identify the predictors of patient and system delay for p-PCI in the period of 2020 at a reference hospital for p-PCI.

Methods

Patients submitted to p-PCI in the period from March to September 2020 were included and compared with the same period in 2019. We analyzed the differences between the two groups regarding the patient's delay times, time from the onset of symptoms to the first medical contact (FCM) and the system (time from the first contact with the health system to p-ICP). Data collection of the patient's previous history, coronary intervention performed and post-PCI follow-up was performed using the electronic patient record. Univariate analysis and logistic regression models from multivariate analysis were used to determine the predictors of “patient delay” and “system delay” and adjusted for confounding factors. The analysis was performed with a significance level of 5%.

Results

We included in the study 255 patients who underwent p-PCI, of which 122 in the period from 2020 and 133 in the period from 2019. Regarding the characteristics of the population, there were no significant differences between the two periods. Regarding the patient's delay time, there were no statistically significant differences. The variable first medical contact with a non p-PCI center was the only variable associated with system delay>90 minutes in the multivariate analysis, OR (6.18: 95% CI, 1.91–20), p=0.002. There was a statistically significant association between the period of 2020 (pandemic period) and total ischemia time, but with a negative effect, dependent variable adjusted for confounding factors [adjusted OR: −0.10; 95% CI: −107.61 to −5.57; p=0.03].

Conclusion

In this study, the patient's admission to a non p-PCI centers was identified as the only predictor of longer delay until p-PCI (system delay). However, these results should serve as a contribution to decision making in order to mitigate risks, regardless of any associated catastrophe and eventually alert the population not to neglect the symptoms suspected of acute myocardial infarction.

Funding Acknowledgement

Type of funding sources: None.

Rapid atrial fibrillation increases cardiac biomarkers: decision to perform coronary angiography based on novel high-sensitivity Troponin I peak

Funding Acknowledgements

Type of funding sources: None.

Background

Since January 2018 the availability of high sensitivity Troponin I (hsTnI) has improved ischemia diagnosis. In patients with rapid atrial fibrillation (AF), the decision to undergo coronary angiography is usually due to elevated cardiac biomarkers. However, evidence to support the rentability of this approach is sparse.

Purpose

Evaluate if hsTnI in patients with rapid AF and elevated cardiac biomarkers has a good discriminative power to predict a positive coronary angiography.

Methods

We retrospectively studied consecutive patients admitted to the emergency department (ED) between January 2018 and December 2019 with rapid AF that underwent coronary angiography and had multiple hsTnI values obtained. We analysed risk factors, initial and peak hsTnI, time from ED admission to peak hsTnI and ST-T segment abnormalities (ST depression and/or T wave inversion). We evaluated the presence of significant coronary artery stenosis with the need of revascularization at coronary angiography. Univariable and multivariable analysis was performed to obtain the Odds Ratio (OR, 95% CI, p-value) for significant coronary artery disease (CAD).

Receiver operator characteristics (ROC) curve and area under the curve (AUC) were obtained to determine the discriminative power of peak hsTnI as predictor of a positive coronary angiography. Optimal cut-point value was obtained (Youden index) and patients were divided according to this value.

Results

From 1407 patients admitted to the ED with rapid AF, 30 patients, 60% male, median age 74 (IQR 61.25-80.75) years, were submitted to coronary angiography. Significant coronary artery stenosis was present in 17 (57%) patients.

Age, ST-T segment abnormalities and peak hsTnI were predictors of significant CAD, respectively 1.203, 1.064-1.361, 0.003; 25.00, 3.522-177.477, 0.001; and 1.000, 1.000-1.001, 0.015.

Optimal cut-point value for predicting the presence of significant coronary artery stenosis at coronary angiography was a peak hsTnI of 359 pg/mL (AUC 0.869, p-value 0.001, 95% CI 0.742-0.995). The two groups with hsTnI < 359 and hsTnI >359 differed in age and ST-T segment abnormalities (see Table).

After adjustment, peak hsTnI >359 pg/mL was the only independent predictor of significant CAD (23.894, 1.310-435.669, 0.032).

Conclusion

In this group of patients with rapid AF, peak hsTnI >359 pg/mL was the only independent predictor of significant coronary artery disease. Therefore, those patients should undergo coronary angiography. Abstract Figure.

Optimal percentage of biventricular pacing to obtain CRT response: how high is high enough

Funding Acknowledgements

Type of funding sources: None.

Background

The greatest benefit with cardiac resynchronization therapy (CRT) is achieved when biventricular pacing (BivP) percentage (%) is close to 100%. However, in some patients that goal can be challenging to obtain.

Purpose

Determine whether a lower BivP% could lead to similar CRT response and events, as compared with patients with BivP% >98%.

Methods

Patients with CRT followed up in a remote-monitoring network were retrospectively analyzed. BivP% was assessed and response to CRT was defined as an absolute increase in left ventricle ejection fraction (LVEF) >5% or a relative increase in LVEF >15%.

Low BivP% was defined as <98%. Clinical, echocardiographic data and all-cause death during follow-up were evaluated. ROC curve and AUC were obtained to determine the discriminative power of BivP% as predictor of CRT response. Optimal cut-point value was obtained and patients were divided according to this value. Kaplan-Meyer survival function was used to compare survival in the different groups and the Log-rank test was used for comparison between the groups.

Results

88 patients, 76% male, median age 73.5 (IQR 65.75-79.25) years were included. A CRT-D was implanted in 69%. Etiology was ischemic in 44%. 93% were under beta-blockers. Median LVEF before CRT was 27% (IQR 20.25-32). 

44 patients (50%) had low BivP% (median 91%, IQR 96-99), 55% due to atrial fibrillation and 52% due to frequent premature ventricular complexes. After optimization of medical therapy, device programming and/or interventional procedures, we obtained a BivP >98% in 26 out of the 44 patients (59%). However, in 18 patients (20%) BivP% was <98% (median 95, IQR 92.25-96). 66% patients were CRT responders. Median follow-up was 36 (IQR 23.75-84) months. During follow-up, all-cause mortality was 27% (24 patients).

Optimal cut-point value for predicting CRT response was 91% BivP% (AUC 0.644, p-value 0.047, 95% CI 0.496-0.792). The characteristics of the two groups didn’t differ significantly (Table).

Survival was significantly higher in patients with BivP% >91% (Log-rank 3.667, p-value 0.050) – Figure.

Conclusion

In this population, BivP% >91% was sufficient to achieve CRT-response and was associated with a better survival. BivP% <91%(n = 4)BivP% >91%(n = 84)p-valueAge in years, median (IQR)72.50 (70.50-73.75)74.00 (65.00-80.00)0.666CRT-D, n (%)3 (75.0)58 (69.0)0.999Ischemic cardiopathy, n (%)3 (75.0)35 (41.7)0.311LVEF before CRT, median (IQR)27 (19-39)27 (20-32)0.795Beta-blockers, n (%)4 (100.0)78 (95.1)0.999Abstract Figure.

Predictors of relapse after improved ejection fraction in patients with heart failure

Background

Patients with systolic dysfunction with improvement in left ventricular ejection fraction (LVEF) present a more favorable clinical profile when compared to those that maintain dysfunction. However, little is known about the characteristics of patients who “relapse” after LVEF improvement.

Purpose

Evaluate prevalence, clinical characteristics and outcomes of patients in whom ejection fraction declined after previous improvement.

Methods

We retrospectively studied patients followed at a heart failure (HF) clinic with LVEF improvement after an initial diagnosis of HF with reduced ejection fraction (EF), which was defined as having an LVEF >40% on follow-up. We then evaluated the presence of LVEF “relapse” in these patients – a decline in LVEF to <50% or <40%, in cases where it recovered to preserved EF or to mid-range EF, respectively. We analysed patient demographics, clinical parameters and outcomes and used logistic regression to assess the predictors of LVEF “relapse”.

Results

98 patients were studied, 70 (71%) male, median age 69 (58–76) years.

Fifty-four (55%) patients had recovered EF (>50%) and in 44 (45%) it had improved to mid-range values. In 36 (37%) occurred LVEF “relapse”: in 10 (10%) patients to an EF 40–50% and in 88 (90%) to an EF<40%.

Ischemic cardiomyopathy and non-ischemic dilated cardiomyopathy were the main HF aetiologies (38% and 35%, respectively).

During a median follow-up of 7 years, 39 (40%) patients had at least one HF hospitalization. Global mortality was 30%, with no significant statistical difference between the two groups.

In univariate analysis, HF duration, type 2 diabetes mellitus (T2DM), left main or left anterior descending coronary (LAD) disease, valvular heart disease (VHD) and chronic kidney disease (CKD) predicted LVEF “relapse”.

In multivariate analysis, T2DM, left main or LAD disease and VHD were the only predictors of LVEF “relapse” (Table).

Conclusion

In this group of patients, LVEF “relapse” after it had initially improved was frequent and was predicted by the presence of T2DM, left main or LAD disease and VHD. Despite improved systolic function, these patients remain at high risk, thus the need to maintain treatment.

Funding Acknowledgement

Type of funding source: None

P1506Prolonged and recurrent hospital admissions predict risk of cardiac implantable electronic device infections in hospitalized patients with bacteriaemia

Background

As the use of Cardiac Implantable Electronic Devices (CIED) is expanding, the burden of device-related infections, particularly infectious endocarditis, is also increasing. Furthermore, with the increase in life expectancy, these devices are being implanted in patients who are older, with more serious co-morbidities and who are frequently hospitalized.

Purpose

To assess incidence and predisposing factors for infective endocarditis (IE) in hospitalized patients with CIED and nosocomial bacteraemia.

Methods

We performed a retrospective analysis of all hospitalized patients with CIED and positive blood cultures admitted to the Cardiology department between January 2012 and February 2019. Endocarditis was defined according to modified Duke criteria. We analyzed clinical parameters, device- and procedure-related characteristics, length of hospital stay and hospitalizations in the previous year.

Results

25 patients had positive blood cultures, 4 patients (16.0%) were diagnosed with infective endocarditis (median age 59.25 years, 75.0% male).

Patients characteristics are displayed in the Table.

In univariable analysis, the number and presence of hospitalizations in the previous year and the length of hospital stay was significantly associated with the possibility of endocarditis (respectively, OR 3.411, 95% CI 1.164-9.998, p-value 0.025; OR 18.000, 95% CI 1.375-235.686, p-value 0.028; and OR 1.047, 95% IC 1.001-1.096, p-value 0.046).

Conclusion

In this group of patients with positive blood cultures during hospitalization, the possibility of CIED infection was predicted by the length of hospital stay and the presence and number of hospitalizations in the previous year.

With CIED-IE Without CIED-IE p-value Age in years, median (IQR) 63 (16) 76 (16) 0.002 Heart failure, n (%) 4 (100%) 10 (47.6%) 0.105 LVEF in %, median (IQR) 21 (9) 51 (30) 0.008 LV dilation, n (%) 4 (100%) 8 (38.1%) 0.039 Device revision/upgrade/substitution, n (%) 2 (50.0%) 6 (28.57%) 0.570 LOS in days, median (IQR) 58.5 (83) 20 (15) 0.004 Hospital admissions in the previous year, n (%) 3 (75.0%) 3 (14.3%) 0.031 No. of hospital admissions in the previous year, mean (standard deviation) 1.67 (1.528) 0.29 (0.784) 0.005 Use of central venous access, n (%) 4 (100%) 4 (19.05%) 0.008 LOS – Length of Stay; LV – Left Ventricle; LVEF – Left Ventricle Ejection Fraction

Autoimmune rheumatic diseases in the intensive care unit: experience from a tertiary referral hospital and review of the literature

Autoimmune rheumatic diseases (AIRD) are not uncommon in the general population and up to one third of hospitalized patients with AIRD may need admission to intensive care unit (ICU). This paper describes the causes of admission, the clinical features and outcome of 24 AIRD patients admitted to a medical ICU from a third level hospital. Thirteen patients had systemic lupus erythematosus (54.2%), three rheumatoid arthritis (12.5%), three pulmonary renal syndrome (12.5%), two dermatopolymyositis (8.3%), two scleroderma (8.3%) and one antiphospholipid syndrome (4.2%). The main causes for ICU admission were rheumatic disease flare-up (37.5%), infection (37.5%) and complications derived from rheumatic disease (29.1%). Mortality during ICU stay was 16.7% (four patients). Excluding shock requiring vasopressor support, no statistical difference was found between survivors and nonsurvivors; although there was a trend to higher test severity scores (APACHE II, ODIN) in nonsurvivors. Our results reveal a lower mortality rate in AIRD patients admitted to the ICU than reported previously. Severity scores such as APACHE II are predictors of mortality in patients with AIRD in the ICU.

Spontaneous Resolution of a Ruptured Dissecting PICA Aneurysm

Spontaneous dissecting aneurysms (SDAs) seldom involve the intradural vertebral artery VA, the posterior cerebral, basilar or postero inferior cerebellar arteries (PICAs), where they produce subarachnoid haemorrhage and/or ischaemia.

These lesions may develop spontaneously or occasionally after minor trauma and occur in young people in whom there is no underlying abnormality to explain the appearance of the dissection in most cases.

Spontaneous dissecting aneurysm of the PICA is rare and its natural history is not well understood. Surgery or endovascular treatment for PICA dissection remain controversial because they suggest vessel occlusion. Only in a few cases is the bypass between the occipital artery and the PICA possible with trapping of the dissected segment. Reinforcement of the arterial wall does not seem efficient and the surgical approach per se with sole exclusion of the aneurysm may be disastrous.

We describe two cases of SDA of PICA that presented with subarachnoid haemorrhage (SAH), treated conservatively, with spontaneous cure of the lesions, angiographically confirmed at mid-time follow-up of five and four months. These favourable spontaneous thromboses, like 11 other similar case reported in the literature, did not show any rebleed. The possibility of a benign clinical course of this lesion exists; clinical and angiographic management of the patient before a decision for a aggressive treatment is proposed.

Mitochondrial analysis sheds light on the origin of hair sheep

A total of 180 mtDNA sequences from hair Caribbean (93), West African (73) and Canarian-wooled (14) sheep were analysed to shed light on the origin of hair sheep. A comparison of 360 Iberian sheep sequences retrieved from GenBank was performed to assess a possible European origin of the Caribbean hair sheep. These 180 sequences gave 48 different haplotypes (16 in Caribbean sheep). All Caribbean and Canarian-wooled sequences and 91.8% of the West African samples belonged to haplogroup B. The sheep analysed showed wide haplotypic identity. Caribbean sheep shared roughly two-thirds of their samples with Canarian-wooled and West African samples, respectively. Principal component analysis showed that the Caribbean and the Canarian-wooled sheep clustered together. Additional analyses showed that hair and Iberian sheep had wide genetic identity. It was not possible to ascertain a single Canarian, African or European origin of the Caribbean hair sheep using mtDNA markers only. European, African and Caribbean hair sheep maternal genetic backgrounds likely result from related domestication events.

Presence of international multiresistant clones of Streptococcus pneumoniae in Colombia

In Colombia, penicillin resistance of Streptococcus pneumoniae invasive isolates recovered from children less than 5 years old has increased from 10% in 1994 to 49.4% in 1999, suggesting the circulation of international resistant clones in the country. A total of 167 S. pneumoniae invasive isolates with diminished susceptibility to penicillin (DSP) were studied. The techniques used were pulsed-field gel electrophoresis (PFGE) and restriction fragment length polymorphism (RFLP) of penicillin-binding proteins (PBPs) genes (2B, 2X, and 1A). Forty-nine serotype 23F isolates were grouped in two clusters: 15 (31%) multiresistant isolates showed PFGE pattern A and PBP I profile, thus making them indistinguishable from Spain23F-1 clone, and 34 (69%) with PFGE pattern C, PBP II profile, and intermediate level resistance (ILR) to penicillin and TMP-SMX, features unique to a Colombian clone. Fifty-five serotype 14 isolates were assigned to PFGE B pattern, PBP III profile, having high-level resistance to penicillin, and TMP-SMX, similar to the France9V variant 14. This same pattern was present in five capsular type 9V isolates. Four serotype 14 isolates were assigned to PFGE pattern F, and appeared to be similar to Slovakia(14)-10 PFGE pattern, although they had different PBP profiles. Nine capsular type 6B and one 6A isolates belonged to PFGE pattern M, similar to Spain6B-2, although they showed different PBP profiles. The remaining 44 isolates, corresponding to serotypes 14, 6B, 19F, and 34, showed variable PFGE and PBP patterns. These results show that as many as two international clones may be circulating in Colombia as well as a unique, widely distributed 23F clone with ILR to penicillin. Additionally, some Colombian isolates capsular type 14 and 6B might be related to Slovakia(14)-10 Spain6B-2 clones, respectively.

Oral-disease prevention in children with cancer: testing preventive protocol effectiveness

Mucositis, gingivitis, herpetic stomatitis and candidiasis are a potential source of systemic infection in patients undergoing chemotherapy. Their severity and incidence may be reduced with procedures based on the prevention and elimination of sources causing oral infection and irritation.

OBJECTIVE

The purpose of this investigation was to evaluate the effectiveness of an Oral Disease Preventive Protocol in children with cancer, subjected to chemotherapy and prior to application of dentobacterial infection control.

MATERIAL AND METHODS

A controlled clinical test was run, with random assignations, on twelve 5-to-12-year-old patients diagnosed with Acute Lymphoblastic Leukemia (ALL) or Lymphoma, evaluated for twelve months, with a total of 154 evaluations. Five patients were boosted with oral physiotherapy, with non-alcoholic 0.05% fluoride mouthwashes, with topical application of myconazole oral gel; seven patients were given instructions on oral physiotherapy.

RESULTS

There were no significant differences between the groups under evaluation (p>0.05). Of the oral complications evaluated, gingivitis registered the highest percentage (60%), followed by mucositis (18%) and candida albicans infection (7%). Most affected were the submandibular and cervical ganglions (59% and 41%, respectively).

CONCLUSIONS

Prior control of sources causing oral infection and irritation effectively prevents complications during non-surgical cancer therapy.

Atrial flutter ablation with a new radiofrequency catheter

OBJECTIVE

To assess the performance of a new radiofrequency catheter, specially designed for inferior vena cava-tricuspid annulus (IVC-TA) isthmus ablation, in the treatment of atrial flutter.

PATIENTS

IVC-TA isthmus ablation was performed in thirteen patients, eleven men and two women, aged 60 +/- 12, with a diagnosis of typical atrial flutter, symptomatic despite anti-arrhythmic therapy. The flutter was present for more than one year in seven patients and was paroxysmal in the remainder. The echocardiogram showed atrial enlargement in six patients. Atrial flutter was an isolated phenomenon in seven patients and in the remainder was associated with arterial hypertension (two patients), ischemic heart disease (two patients) and dilated cardiomyopathy (two patients).

METHODS

In the electrophysiologic study four diagnostic catheters were used, including one duodecapolar for mapping the tricuspid annulus. In the patients who presented with sinus rhythm, atrial flutter was induced with programmed atrial stimulation, and then the atrial activation circuit was mapped. To demonstrate the entrainment phenomenon the IVC-TA isthmus was over-stimulated, to prove that this was the slow zone of the circuit. The radiofrequency energy was applied in the IVC-TA isthmus with the Medtronic Cosio-Fluttr ablation catheter, for 60 sec per application, with temperature control and with a maximum energy output of 50 W. Criteria for success were not only the disappearance of the atrial flutter during the application of radiofrequency energy, but also the demonstration of bi-directional IVC-TA isthmus block.

RESULTS

The primary success rate was 100%. The mean procedure time was 110 +/- 22 min, mean fluoroscopy time was 23 +/- 4 min and the number of radiofrequency energy pulses was 9 +/- 3. There were no complications. The patients were followed for a mean time of 8 +/- 4 months and atrial flutter recurred in only one patient (8%).

CONCLUSIONS

Atrial flutter ablation with the new Medtronic Cosio-Fluttr catheter, specially designed for the application of radiofrequency at the IVC-TA isthmus, is a safe procedure and has a high success rate. It simplifies ablation, decreasing the number of radiofrequency energy pulses, without using long sheaths and keeping short procedure and fluoroscopy times.

[Deciding about pacing mode in sinus node dysfunction: should carotid sinus massage be performed and in which circumstances?]

OBJECTIVE

To state the incidence of carotid sinus syndrome (CSS) with atrioventricular node manifestation in patients with sinus node dysfunction (SND) and indication for a definitive pacemaker (PM), we propose a new protocol between atrial pacing AAI and double chamber DDD.

POPULATION AND METHODS

69 patients (PTS) (male 71%), median age 65 +/- 10 years, with SND (normal PQ and no intraventricular conduction defect), that had a PM implant following the protocol that included carotid sinus massage for the pacing decision, were followed prospectively between December 1995 and November 1999. During the protocol we implanted DDD PM in PTS with Wenckebach less than 130 or Wenckebach equal/over 130 and CSS. At least, in PTS with Wenckebach equal/over 130 and no CSS we implanted AAI PM. The follow-up was between 4 months and 4 years, with clinical evaluation in the first and fourth months and then half yearly, with carotid sinus massage in the first evaluation.

RESULTS

About 1/4 of the 69 patients followed had SND without carotid sinus syndrome, or atrioventricular node repercussion; the SND involved the atrioventricular node in 56% of the patients, and there was a relation between the SND and carotid sinus syndrome in 18.8%. The follow-up revealed, in all patients, a complete remission of the symptoms, and when we repeated the carotid sinus massage in the first evaluation, there was a response like in the surgery room, in all patients.

CONCLUSIONS

There is a significant number of patients with SND and carotid sinus syndrome. The carotid sinus massage performed in the surgery room does not influence the test sensitivity and specificity in the diagnosis of carotid sinus syndrome. The authors think that carotid sinus massage should be considered in the protocol that defines the pacing mode, in patients with SND, and that influence the choice of pacemaker in 18.8% of patients.

Pneumococcal surface protein A of invasive Streptococcus pneumoniae isolates from Colombian children

Pneumococcal surface protein A (PspA) elicits protection in mice against fatal bacteremia and sepsis caused by genetically diverse pneumococci and protects against carriage and lung infection. We determined the PspA families of invasive isolates of Streptococcus pneumoniae recovered from Colombian children <5 years of age. That 97.5% of Colombian isolates belong to PspA families 1 and 2 supports the hypothesis that a human PspA vaccine covering a few PspA families could be broadly effective.

[A seroepidemiological survey on the island of São Luis during a dengue epidemic in Maranhão]

The island of São Luis in the State of Maranhão, constituted by the municipalities of São Luis-SL (835,428 inhabitants), São José de Ribamar-SJR (60,633 inhabitants) and Paço do Lumiar-PL (80,274 inhabitants), has been suffering dengue (DEN) fever epidemics since 1995, caused by DEN-1. In 1996, from August through October, an aleatory sero-epidemiologic survey was carried out in order to estimate the incidence of DEN infection and to analyze other clinical and epidemiological parameters. A questionnaire was applied and serum samples were simultaneously obtained. Serum samples were tested by hemagglutination inhibition (HI). Results were analyzed using Lotus 123, Epi-info 6.0, Excel 5.0 and STATA softwares. A total of 1,217 serum samples were obtained (101 of PL, 100 of SJR and 1017 of SL). The rate of DEN was 55.4% in PL, 28% in SJR and 41.4% in SL, suggesting the occurrence of 401,933 infections. No difference was seen between males and females, but infection occurred more in the upper social class than in poor people (p < 0.003), and was more frequent in adults than in children (p < 0.0004). In SL, the incidence was stratified into seven sanitary districts (SD), and prevalence was found to range from 26.1% in SD4 to 56.8% in SD1 (p < 0.0001). Symptoms were more frequently reported by people whose HI was positive: they included fever, headache, chills, dizziness, retrobulbar pains, muscle and joint pains, nausea, anorexia and skin rash. In spite of the high incidence of infection, no hemorrhagic cases were reported.