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Doenças Cardiovasculares e Diagnóstico

Volume 4, Emitir 4 (2016)

Artigo de Pesquisa

An Implantable Pressure Sensor for Long-term Wireless Monitoring of Cardiac Function -First Study in Man

Henrik Casimir Ahn, Baz Delshad, Jacek Baranowski

Background: Heart failure is a huge health problem. The possibility of long-term monitoring heart function more accurately in these patients has gained increasing interest. The primary aim of this study was to see if a wireless pressure sensor can be safely implanted to give accurate and reproducible long-term intracardiac pressure recordings. Another aim was to see if there are any adverse effects connected with the implant. A control group was included for comparison of clinical data.

Methods: Forty patients with heart failure, 31 scheduled for open heart surgery and 9 for transcatheter aortic valve replacement (TAVR) were included to test the safety and feasibility of the Titan™ pressure sensor. The patients were randomized to the implant or control group.

Findings: Initial sensor measurements showed very good correlation with reference pressure values from a fluid-filled catheter, and there was no need for calibration of the sensor. At the 6-month follow-up 11 patients had been wearing the implant for >1 year with a median time of 560 days. Ten of these had adequate sensor function. Compared to the control group there was no difference in adverse clinical events and the overall number of complications was low.

Conclusions: This first study in man on a new implantable wireless hemodynamic monitor showed favorable results regarding our primary endpoints; accuracy of recordings over time and safety profile. The technology has great potential for monitoring at home since it is easy to use in the out-patient setting.

Relato de caso

Axillofemoral Bypass for Critically Ischemic Lone Lower Limb: A Mercy Trial in a Final Exam or a Simple Remedy for an Impending Disaster?

Abdulsalam Y. Taha

Critical limb ischemia with rest pain and/or tissue loss is a serious sequel of occlusive aortoiliac disease (AID) inevitably leading to amputation unless a timely successful revascularization is performed. The most effective therapy is aorto (bi) femoral bypass while endovascular intervention has an increasing role in lesions of favorable anatomy. However, there is a group of poor risk patients with co-morbidities who neither tolerate a major aortic surgery nor being suitable for endovascular therapy. For such patients, extra-anatomical bypass such as axillofemoral bypass, first used in 1963, emerges as an effective alternative. Herein, we describe the case of an Iraqi male, 65 year old with critically ischemic lone lower limb due to total occlusion of infra-renal aorta with a very poor distal runoff who underwent a successful axillofemoral bypass that relieved his pain and saved his single lower limb. The graft was patent 5 months following the operation as shown by Doppler ultrasonography (DUS) though longer follow up was not available. In conclusion, axillofemoral bypass is relatively a simple operation for a serious disease. Limb loss was inevitable in this patient without this ‟mercy trial ״. The alternative choice was either amputation or a major aortic surgery with a doubtful benefit and a definite morbidity.

Artigo de Pesquisa

Does Anesthesia Induction during Electrophysiologic Studies Induce Tachycardia in Pediatric Patients

Manoj Gupta, Jill Shivapour, Ann Lawrence, Christopher Snyder

Background: Anesthesia is essential to facilitate the majority of pediatric electrophysiology studies (EPS); however, a risk of an arrhythmia exists during its induction. The purpose of this study was to determine the incidence of arrhythmia during anesthesia induction in pediatric EPS.

Methods: IRB approved retrospective review of pediatric EPS from 1/99 to 1/14. Inclusion criteria: Age ≤ 21 years and comprehensive EPS under general anesthesia. Data collected: demographics, EPS results, and anesthesia records. Patients were grouped based upon route of anesthesia administration: Intravenous (IV) agents (propofol, ketamine, and kentanyl) and Inhalational (IH) agents (sevoflurane, isoflurane and desflurane).

Sinus Tachycardia (STACH) was defined as variable heart rates of >140 and <180 beats per minute (bpm) originating from sino-atrial node with a duration of ≥5 minutes. Supraventricular Tachycardia (SVT) was defined as an abnormal heart rhythm arising due to abnormal electrical activity of the heart, originating proximal to the bundle of His, with sustained rates ≥ 180 bpm.

Results: Inclusion criteria were met by 378 patients, 57% male, median age 14 ± 4 years, with IV induction utilized in 275 (72%) patients. During induction, 39 (10%) developed tachycardia: 38 STACH and 1 SVT. STACH was more common with IH anesthesia when compared to IV (p<0.0001). Patients with Wolff-Parkinson-White (WPW), irrespective of anesthesia type, had twice the risk of developing STACH, 17/114 vs. 21/264 of others (p = 0.02).

Conclusion: Sinus Tachycardia occurred in 10% of pediatric electrophysiology cases performed under anesthesia. It was seen more frequently when IH agents were used compared to IV. Patients with WPW have
double the risk of developing sinus tachycardia during anesthesia induction when compared to patients with other forms of SVT.

Artigo de Pesquisa

Comparison of Neointimal Tissue Characteristics Between Bare-metal and Second-generation Drug-eluting Stents Nine Months after Implantation in Patients with ST-segment Elevation Myocardial Infarction

Koichiro Sonoda, Satoshi Ikeda, Shiro Hata, Toshihiko Yamasa, Hiroki Shinboku, Yuji Matsumoto, Fumio Fukukawa, Yasushi Takahara, Shin-ichi Haruta, Shingo Yatani, Seiji Koga, Koji Maemura

Background: Neointimal tissue characteristics after implantation of stents are related to late/ very late stent thrombosis and/ or restenosis of target lesion. However, the difference of them has not been fully elucidated among bare-metal stents (BMS) and second-generation drug-eluting stents (DES).

Methods: The present study uses optical coherence tomography (OCT) to compare neointimal tissue characteristics among BMS (n = 22), Endeavor zotarolimus - (E-ZES; n = 21), everolimus - (EES; n = 22) and
biolimus A9 - (BES; n = 23) eluting stents in the patients with STEMI who underwent follow-up coronary angiography at nine months after stent implantation.

Results: Quantitative coronary angiography revealed significantly higher restenosis rates for BMS and E-ZES than EES and BES. OCT showed significantly lower and higher rates for covered and uncovered EES, respectively, than for BMS and E-ZES. The malapposition rate for E-ZES was significantly lower than those of other two types of DES. The neointima of EES and BES was significantly thinner than that of BMS and E-ZES. Evagination was more prevalent in BES among the four stents, and the rate of evagination/strut significantly correlated with positive remodeling (r = 0.312, p = 0.006).

Conclusion: Neointimal tissue characteristics were different among BMS and second-generation DES at nine months after implantation into patients with STEMI. This might be related to the differences of future cardiac events.

Artigo de Pesquisa

All-cause Mortality of High-normal Random Blood Glucose using Basic Demographics

Sunil E Saith, Jun Tang, Greg Irving, Shamma A Al Memari, Afra D Al Dhaheri, Fatimah S Alhamlan, Mahdi A Shkoukani, Andrew Kohut

Abstract

Background: The prevalence of diabetes has reached epidemic proportions both in the United States and worldwide. A recent World Health Organization (WHO) report has estimated the prevalence has quadrupled in just three decades and is directly responsible for the deaths of 1.5 million people worldwide. More than 80% of these deaths occur in low and middle income countries. The forecasted urban population in developing nations is expected to double by the year 2030, compared to the year 2000.

Methods: We utilized a limited teaching dataset from the Framingham Heart Study to examine the relationship between blood glucose levels and mortality using a Multivariate Cox proportional hazards model, adjusting for age, gender, body mass index and blood pressure. We divided glucose according to four categories, with normal reflecting conventional “intensive” control, high-normal reflecting a higher glucose level and moderate and severe elevations for further comparison of relative mortality.

Results: 3,270 subjects were followed for 20 years, of which 316 fell into a high normal blood glucose category and 2,885 subjects had a normal blood glucose. The relative risk of death in the high normal random blood glucose (RBG) group was 1.22 times that of those with a random normal blood glucose (95% CI: 1.021.45; pvalue = 0.030).

Discussion: A high normal random glucose level with limited covariates may prognosticate a greater risk of allcause morbidity and mortality compared to low normal glucose levels. These findings may help to provide estimates of risk in low and middle-income countries, where there is limited access to healthcare and basic lab testing such as HgbA1c.

Comunicação curta

Algorithms of Relationships between Left Ventricle Dysfunction and Atrial Fibrillation

Vladimir Tilman

Abstract

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Many studies have investigated the cause for the development of AF in the left ventricle dysfunction. Recently the hypothesis was proposed that atrial fibrillation is a protective physiological mechanism, based on the termination of atrial mechanical systole. This reduces the enddiastolic pressure in the left ventricle by excluding the component of systolic left atrial pressure from the total enddiastolic pressure and, respectively, in the system of the pulmonary veins and alveolar capillaries in situation of the left ventricle dysfunction, and thus reduces the likelihood for development of pulmonary congestion. First of all this hypothesis explains relationship between left ventricle dysfunction and AF. The hypothesis helps to build algorithms of the development AF in the cases of the left ventricle dysfunction in the various diseases and conditions.

Comunicação curta

How Can we Improve Non-Surgical Septal Reduction for Hypertrophic Obstructive Cardiomyopathy?

John H Cleator, Ehab S Kasasbeh, David X Zhao, Douglas B Sawyer

The goal for treatment of medical refractory Hypertrophic Obstructive Cardiomyopathy (HCM) is reduction of the hypertrophied left ventricular septum which obstructs blood flow. A surgical approach consists of an open-heart myomectomy, while the less invasive percutaneous approach involves creating a myocardial infarction by injecting 95 to 100% ethanol through a septal artery, a procedure termed alcohol septal ablation (ASA). Although less invasive than myomectomy, there are several limitations of alcohol septal ablation. The most important appears to be full thickness infarction that is often complicated by heart block and ventricular tachycardia/fibrillation. The ideal therapy for septal hypertrophy would be to find an agent that induces a less severe injury and/or atrophy of the hypertrophied septum. We review several alternative techniques for selective injury of the septum and describe the ideal characteristics of such an ideal agent. Our central hypothesis is that the anthracycline antibiotic such as doxorubicin may be the perfect agent. Anthracycline-based chemotherapies have been used in the treatment of solid and hematological tumors for many years. These agents have known cardiotoxic side effects that are related to cumulative dose which can lead to heart failure. Although the mechanism of action of doxorubicin cardiotoxicity is controversial, it is very clear that these agents cause atrophy of the myocardium, induce apoptosis and necrosis, as well as anti-angiogenic effects. We propose that selectively treating the hypertrophied septum of HCM patients with injection of the anthracycline doxorubicin will lead to superior outcomes compared to ASA.

Artigo de revisão

Gla-rich Protein (GRP): A New Player In The Burden Of Vascular Calcification

Carla SB Viegas, Dina C Simes

Vascular calcification is a life-threatening complication of cardiovascular disease and an independent risk factor for morbidity and mortality. It is a complex and active cellular process that includes multiple players and regulators resembling physiological bone formation. Currently, it is generally accepted that our understanding of the molecular aetiology of vascular calcification remains incomplete. Endogenous inhibitors play a critical role in preventing vascular calcification. A relation between vitamin K and vascular calcification has been widely established and recently, the vitamin K-dependent protein, Gla-rich protein (GRP), was proposed to have an important role in vascular calcification inhibition, with clinical implications.

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