Ivabradine to Treat Inappropriate Sinus Tachycardia after the Fast Pathway Ablation in a Patient with Severe Pectus Excavatum

We present the case of a 49‐year‐old woman with atrioventricular nodal re‐entrant tachycardia and a severe pectus excavatum. The patient underwent an electrophysiological study and fast pathway ablation. Fast pathway ablation was not done on purpose but accidentally, likely due to the abnormal position of the heart in the chest cavity in this patient suffering from severe pectus excavatum. Some hours after the ablation, the patient developed inappropriate sinus tachycardia (IST), complaining of dyspnea and fatigue. IST has been described as a complication of fast pathway ablation in 10% of the cases. In our case it was not possible to treat IST with β‐blockers due to an important lowering of the blood pressure. Digitalis, given as second choice, was not successful. Ivabradine—the specific sinus node If current inhibitors—was used to successfully lower the heart rate with immediate relief of symptoms. A 24‐hour Holter, 10 days later, showed a complete control of the heart rate without any episode of IST. The patient was completely symptom free and able to undertake her normal daily activities without any discomfort. Our case confirms the potential use of ivabradine for indications other than coronary artery disease. (PACE 2010; 33:e32–e35)     

The Complexity of Mechanisms in Ventricular Tachycardia

Several pathophysiological substrates may be responsible for ventricular tachycardia (VT) occurring in the chronic phase of a myocardial infarction. Reentrant circuits can have anatomical or functional characteristics. Macroreentrant or microreentrant circuits have been described. Activation maps have shown that the circuit can be represented as a single loop or as a figure-of-eight reentrant pattern. All these different substrates have in common that they result in sustained monomorphic VT. The adequate treatment will probably be different for each one of them. In this article, some possible pathophysiological substrates of VT occurring in the chronic phase of a myocardial infarction are reviewed. Finally, we speculate on how catheter ablation may modify each one of the substrates.     

A Fast and Reliable Algorithm to Localize Accessory Pathways Based on the Polarity of the QRS Complex on the Surface ECG During Sinus Rhythm

d 'AVILA, A., et al .: A Fast and Reliable Algorithm to Localize Accessory Pathways Based on the Polarity of the QRS Complex on the Surface ECG During Sinus Rhythm . Background: Many criteria have been published to localize accessory pathways from the 12-lead EGG during sinus rhythm. This study analyzed whether the localization of an accessory pathway could be predicted by using the polarity of the QRS complex during sinus rhythm on the surface ECG, instead of the delta wave polarity as used in many reports. Methods: The ECGs of 140 patients with an overt and single accessory pathway were evaluated. Eight localizations were taken into account. The precise location was previously known from successful radiofrequency ablation sites. Results: In 128 patients (92%), the new algorithm allowed an accurate diagnosis of the site of implantation of the accessory pathway. Conclusion: Analysis of the polarity of the QRS complex on five electrocardiographic leads provides an easy, fast and reliable way to localize accessory pathways during sinus rhythm.     

Acral Melanoma Simulating Warts: Dermoscopic Clues to Prevent Missing a Melanoma

BACKGROUND: Acral melanoma may adopt a variety of clinical characteristics simulating other tumors, ulcers, hemorrhage, or infections. In the Caucasian population health care providers often misdiagnose acral melanoma, and this is the cause of inadequate treatments. Clinical and dermoscopic clues can be easily recognized, which help to prevent missing a melanoma. OBJECTIVES: To study the clinical and dermoscopic findings in three cases of acral melanoma simulating warts that had been treated by dermatologists with curettage and cryotherapy. MATERIAL AND METHODS: Clinical and dermoscopic study of the tumors and review of the most frequent simulators of acral melanoma reported in the literature. RESULTS: In all three tumors, hyperkeratosis and the lack of specific pigmentation were observed. The parallel ridge pattern, revealed by dermoscopic examination, precipitated the recognition of acral melanoma. CONCLUSION: In these cases that presented atypical characteristics of acral lesions, therefore challenging the diagnostic process, dermoscopic examination helped to confirm an accurate diagnosis of acral melanoma.     

Right-Sided Versus Left-Sided Radiofrequency Ablation of the His Bundle

Radiofrequency (RFJ ablation of the His bundle was attempted in 30 consecutive patients with atrial flutter or fibrillation. A 7 French quadripolar catheter with a 4-mm distal electrode was advanced from the right femoral vein (21 patients), or subclavian vein (two patients) and positioned across the tricuspid valve. Adequate His-bundle potentials were obtained in all patients. However, in six patients atrioventricular (AV) block could not be obtained after multiple (mean = 8) applications of RF energy from the conventional right-sided approach. In these patients the same catheter was advanced to record a His potential through a retrograde arterial approach. AV block was created in all patients with one to three applications of RF energy. The duration of the procedure was 22 to 90 minutes for the right-sided approach and 5 to 10 for the left-sided approach (P < 0.005). Subsequently, in seven patients a left-sided approach was used first. One to six applications of RF energy were required to create AV block. The radiation exposure time was 3 to 20 minutes. No complications occurred. Conclusions: RF ablation of the His bundle seems easier using a left-sided than a right-sided approach, reduces procedure and radiation time, and avoids recovery of conduction. These data suggest that a left-sided approach, in spite of requiring arterial catheterization, may be preferable to a right-sided approach.     

DD genotype of angiotensin-converting enzyme in type 2 diabetes mellitus with renal disease in Mexican Mestizos

Aim:   The DD genotype of angiotensin-converting enzyme (ACE) has been suggested as a major contributor of diabetic nephropathy in several populations. The purpose of the present study was to determine whether micro/macroalbuminuria is associated with ACE insertion/deletion (I/D) polymorphism in Mexican Mestizos with type 2 diabetes mellitus.
Methods:   A total of 435 patients with type 2 diabetes mellitus, of whom 233 had albuminuria, were characterized for the ACE I/D polymorphism by the polymerase chain reaction method.
Results:   Clinical and biochemical characteristics and frequencies according to DD, ID and II genotypes in patients with and without albuminuria showed no significant differences. However, only females with micro/macroalbuminuria showed higher frequency of a DD genotype than those without albuminuria (27.9%, 21.2% and 10.5%, respectively; P  ≤ 0.044). In addition, female patients with macroalbuminuria without dialysis showed no significant differences with patients undergoing dialysis.
Conclusion:   The ACE DD genotype is a risk factor for the development of renal disease in Mexican Mestizo females with type 2 diabetes, indicating a possible DD genotype-associated sex effect in renal disease.