Incidence of new onset atrial fibrillation in patients with permanent pacemakers and the relation to the pacing mode.

BACKGROUND: Atrial fibrillation is a relatively common arrhythmia often seen in patients with permanent pacemakers. In this study we aimed to assess the incidence of atrial fibrillation in patients whose pacemakers were programmed to pace in the right ventricle (VVI) and compared it with patients whose pacemakers were programmed in non-VVI mode(i.e. AAI or DDD). MATERIAL AND METHODS: Records of the patients with permanent pacemaker or implantable-cardioverter-defibrillator were evaluated and analyzed. These patients had regular periodic follow-up evaluation over the last 10 years. (January 1, 2002 to December 31, 2012). Patient demographic, pacemaker data, pacing mode, review and analysis of arrhythmia log for occurrence of new atrial fibrillation and echocardiographic findings for left atrial size, mitral regurgitation, were analyzed and recorded. Left atrial size was classified as mild, moderate or severe enlargement, depending on the left atrial dimension. RESULTS: Average age was 68 years. There was no gender predominance (51% male). Mean follow-up duration was 6 years and 3 months. Hispanic population represented the majority of the patients (65.4%). Majority of the devices (80.0%) were programmed as DDD pacing mode. Fifty-five patients (52.8%) did not develop atrial fibrillation. 85.7% of the patients paced in VVI-mode had atrial fibrillation while atrial fibrillation occurred in 37.4% among patients paced in non-VVI-mode. This difference was statistically significant (P<0.0001). CONCLUSIONS: Right ventricular pacing in a VVI mode was associated with higher incidence of atrial fibrillation, mitral regurgitation and left atrial enlargement. Non-VVI based pacing demonstrated lower incidence of new onset atrial fibrillation.

Success rate of catheter ablation in atrial flutter: comparison of a 4- or 5-mm tip electrode catheter with an 8-mm tip electrode catheter.

BACKGROUND: Radio frequency (RF) energy is capable of interrupting the reentrant circuit of atrial flutter and curing the arrhythmia. The development of 8-mm tip catheter provides more tissue damage and has offered the promise of improved success. The purpose of our study was to determine if the acute and long-term success with the 8-mm tips were superior to the 4- or 5-mm tips. MATERIALS AND METHODS: The outcomes of the first 20 patients in whom an 8-mm tip catheter was used were compared with the previous 20 patients in whom a 4-or 5-mm tip catheter was used. Procedural (acute) ablation success was defined by creation of bi-directional isthmus block. Long-term success was defined as the prevention of clinically evident atrial flutter (AFl) as determined by the absence of symptoms or maintenance of sinus rhythm on electrocardiogram, six months to one year after the procedure. RESULTS: Compared to the 4- or 5-mm tip, the 8-mm catheter tip was associated with a reduced ablation duration {22.3 +/- 16 versus 11.5 +/- 5 min (p = 0.0078)}, a lower mean number of ablations {13.5 +/- 9.9 versus 6.8 +/- 2.9 (p = 0.0065)} and a reduced procedure time {1.8 +/- 0.7 versus 1.1 +/- 0.5 h (p = 0.0032)}. Acute success was 95% in the 4- or 5-mm group versus 80% in the 8-mm group (p = NS), but long-term success was higher in the 8-mm group than the 4- or 5-mm group (87.5 versus 63.2%, p = 0.0436). CONCLUSIONS: Eight-millimeter tip catheters for AFl shorten procedure time, reduce the duration and number of ablations and accomplish bi-directional block when compared with smaller tipped catheters. The long-term success rate is better with the 8-mm tips and should be the preferred catheter for RF ablation of AFl.

Use of Chronic Disease Registries to Optimize Cardiovascular Health.

Cardiovascular disease remains a significant cause of mortality and morbidity despite relentless ongoing research all over the world. The different cardiovascular societies and research organizations are in a constant effort to improve overall cardiovascular (CV) outcome by conducting trials and establishment of guidelines. The ever growing health care costs have enforced governmental agencies to develop quality performance measures which are addressed towards increasing quality, safety, efficiency of patient care and to curtail the cost of health care. Clinical registries are observational databases which provide detailed information about patient population, a specific disease or a clinical condition, therapy or procedure. These can be utilized in estimating appropriateness of health care delivery and providing feedback to providers and health care organizations for gauging their performance at regional and national level. The introduction of electronic health records (EHR) has immensely helped the workflow and maintenance of clinical registries with their integrated software.

Cardiac Trauma.

Cardiac trauma is a leading cause of death in the United States and occurs mostly due to motor vehicle accidents. Blunt cardiac trauma and penetrating chest injuries are most common, and both can lead to aortic injuries. Timely diagnosis and early management are the key to improve mortality. Cardiac computed tomography and cardiac ultrasound are the 2 most important diagnostic modalities. Mortality related to cardiac trauma remains high despite improvement in diagnosis and management.

Paclitaxel-Coated Balloons: Review of a Promising Interventional Approach to Preventing Restenosis in Femoropopliteal Arteries.

Peripheral arterial disease (PAD), a major cause of morbidity and mortality worldwide, is characterized by intermittent claudication and is associated with chronic diseases such as diabetes and hypertension. The goal of treatment is to address the underlying cause and to modify risk factors. Although medical management is the first-line treatment of PAD, some individuals may have severe symptoms and require revascularization with percutaneous transluminal angioplasty with or without stent placement or surgery. Interventional approaches may, however, be associated with high prevalence of restenosis and subsequent complications such as critical limb ischemia and amputation. Drug-eluting balloons (DEBs) are a new interventional technology with the primary goal of preventing restenosis. We review the clinical trials and studies that assessed the efficacy and safety profile of DEB and will focus on the restenosis rate in femoropopliteal arteries including target lesion revascularization (TLR) and late lumen lesion (LLL) using different modalities of intervention such as stents and DEB. Average data collected from the trials reported included restenosis rate of 25%, 0.3 mm LLL, and 14% reduction in TLR with DEB versus uncoated balloons. Below the knee (BTK) only intervention studies were excluded from this review as endovascular approach is usually reserved for critical limb ischemia for BTK disease. Interventional approach to treat PAD with DEB appears to be a promising technology. Additional larger studies are needed to further define safety, efficacy, and longer term outcome with this novel technology.

Systemic Hypertension in Patients with Aortic Stenosis: Clinical Implications and Principles of Pharmacological Therapy.

The treatment of systemic hypertension (HTN) in patients with Aortic stenosis (AS) requires a careful balance of lowering the systemic blood pressure without compromising vital organ perfusion and worsening of the symptoms of AS. Treatment of systemic HTN is beneficial because the combination of HTN and AS provides additional overload to the left ventricle. This leads to secondary Left ventricular hypertrophy (LVH), which has been shown to increase cardiovascular risks and mortality and thus early presentation of symptoms of AS. Additionally, presence of HTN may affect the accurate assessment of AS. Different treatment options are available, however no specific treatment guidelines have been established for patients with concomitant AS and HTN. Improved control of HTN is the key to prevent symptom progression and inadvertent early surgery. Angiotensin converting enzyme inhibitors (ACEi) and Angiotensin receptor blockers (ARB) appear to be beneficial. Reassessment of the aortic valve by echocardiography is recommended after HTN is well controlled before deciding on aortic valve replacement (AVR).

Clinical Pharmacology and Role of Edoxaban in Contemporary Antithrombotic Therapy.

Edoxaban is a factor Xa inhibitor that is approved for prevention of stroke in individuals with atrial fibrillation and treatment of venous thromboembolic disease at once daily 60 mg dose for individuals with normal renal function. A decrease of dose to 30 mg is recommended for those with moderate renal insufficiency, weight ≤ 60 kg or simultaneous administration of strong P-glycoprotein inhibitors. At this time, it is not recommended for use in persons with either end stage renal disease or with GFR exceeding 95 mL/min. Shorter half-life averaging 8-10 hours may translate into a safer profile. With a fast onset of action of ~1.5 hours and relatively high bioavailability, edoxaban is an alternative for patients who may not be good candidates for warfarin therapy due to multiple limitations that vitamin K anticoagulation entails. No clear benefits of edoxaban have been reported to date compared to the other available factor Xa inhibitors.

A Review of Sodium Glucose Co-transporter 2 Inhibitors Canagliflozin, Dapagliflozin and Empagliflozin.

Sodium glucose co-transporter 2 (SGLT2) inhibitors are a new class of anti-diabetic medications. Canagliflozin was the first drug approved in this group in 2013 and subsequently dapagliflozin was approved in January 2014 and empagliflozin was approved in August 2014. Preclinical studies have demonstrated safety, tolerability, and efficacy in terms of glycemic control and HbA1c level in type 2 diabetes mellitus (T2DM) patients in comparison to other anti-diabetic drugs. The U.S. Food and Drug Administration (FDA) recently released a warning that some of the patients who used SGLT2 inhibitors developed diabetic ketoacidosis (DKA). Empagliflozin has showed safety in type 2 diabetics with renal impairment. Each of these medications can be used as a single treatment or in combination with other anti-diabetic medications.

Review of newer anticoagulants and anti-platelet agents in acute coronary syndrome and cardiovascular diseases.

In the last few years three new oral anticoagulants-Dabigatran, Rivaroxaban and Apixaban and two new antiplatelet agents Prasugrel and Ticagrelor have been approved for use. Dabigatran, Rivaroxaban and Apixaban have been approved for the prevention of stroke and systemic embolism in non valvular Atrial Fibrillation in the United States. Rivaroxaban is also approved for the prevention and treatment of venous thromboembolism, including pulmonary embolism. These drugs have been shown to be non-inferior to Warfarin. These drugs do not need monitoring and have lesser drug interactions compared to Warfarin. The newer antiplatelet agents Prasugrel and Ticagrelor are more potent than Clopidogrel and are more effective in patients with CYP2 C19 enzyme deficiency. Both of these drugs are approved in acute coronary syndrome and Prasugrel is approved only in acute coronary syndrome with percutaneous coronary intervention.

Natural History of Saphenous Vein Grafts.

Aortocoronary saphenous vein graft is an effective treatment of coronary artery disease and a means of markedly improving long-term prognosis in certain patient subgroups. However, there is a significant failure rate with these conduits. Early failure occurs within the first 1-2 months, most likely from primary thrombosis. Intermediate failure is usually caused by the development of neointimal hyperplasia. Late failure occurs after 3-5 years and results from accelerated atherosclerosis. The impact of saphenous vein graft failure on cardiovascular outcomes is significant, and it is important to implement appropriate therapeutic strategies to prevent or minimize failure rates.

Pyridostigmine-induced high grade SA-block in a patient with myasthenia gravis.

PATIENT: Female, 70 FINAL DIAGNOSIS: SA block induced by pyridostigmine Symptoms: Asymptomatic Medication: Pyridostigmine Clinical Procedure: Pacemaker insertion Specialty: Electrophysiology. OBJECTIVE: Unusual clinical course. BACKGROUND: Myasthenia gravis requires a long-term treatment with a parasympathomimetic agent, which may result in bradycardia and asystole. Pharmacologic treatment with a reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH) and Methylprednisolone is seen to improve the muscular symptoms but may reinforce potential bradyarrhythmias. This potential side effect can be treated with the levo isomer of atropine, Hyoscyamine, or Glycopyrollate in an intact conduction system. CASE REPORT: A 70-year old Caucasian female patient with a family history of myasthenia gravis presented with mild weakness of the bilateral facial muscles, moderate dysarthria, dysphagia, diplopia predominantly on the right side and difficulty tracking ocular movements bilaterally. The treatment with pharmacological agents was initiated. Subsequently she developed asymptomatic bradycardia and SA-block. An improvement on Hyoscyamine failed to appear. A dual chamber pacemaker was placed. CONCLUSIONS: In symptomatic or asymptomatic bradycardia with significant high grade SA-block in patients with myasthenia gravis the insertion of a permanent pacemaker can be the definitive solution.

Early detection and prediction of cardiotoxicity in chemotherapy-treated patients.

As breast cancer survival increases, cardiotoxicity associated with chemotherapeutic regimens such as anthracyclines and trastuzumab becomes a more significant issue. Assessment of the left ventricular (LV) ejection fraction fails to detect subtle alterations in LV function. The objective of this study was to evaluate whether more sensitive echocardiographic measurements and biomarkers could predict future cardiac dysfunction in chemotherapy-treated patients. Forty-three patients diagnosed with breast cancer who received anthracyclines and trastuzumab therapy underwent echocardiography and blood sampling at 3 time points (baseline and 3 and 6 months during the course of chemotherapy). The LV ejection fraction; peak systolic myocardial longitudinal, radial, and circumferential strain; echocardiographic markers of diastolic function; N-terminal pro-B-type natriuretic peptide; and high-sensitivity cardiac troponin I were measured. Nine patients (21%) developed cardiotoxicity (1 at 3 months and 8 at 6 months) as defined by the Cardiac Review and Evaluation Committee reviewing trastuzumab. A decrease in longitudinal strain from baseline to 3 months and detectable high-sensitivity cardiac troponin I at 3 months were independent predictors of the development of cardiotoxicity at 6 months. The LV ejection fraction, parameters of diastolic function, and N-terminal pro-B-type natriuretic peptide did not predict cardiotoxicity. In conclusion, cardiac troponin plasma concentrations and longitudinal strain predict the development of cardiotoxicity in patients treated with anthracyclines and trastuzumab. The 2 parameters may be useful to detect chemotherapy-treated patients who may benefit from alternative therapies, potentially decreasing the incidence of cardiotoxicity and its associated morbidity and mortality.

Syncope with a twist.

Left atrial ball thrombus is an uncommon entity, seen more commonly in the presence of mitral valve disease. We present here a case of a large left atrial thrombus presenting as sudden cardiac death.