Set a medium saucepan of water over high heat, and bring the water to a boil. Add the shrimp and boil until the shrimp are just cooked through, 45 to 60 seconds. Drain and immediately plunge the shrimp into the ice water to stop them from cooking further. Drain.
In a serving bowl, mix together the shrimp, hearts of palm, cucumber, tomatoes and basil. Toss with the dressing. Serve.
In a small bowl, whisk together the vinegar, olive oil, agave nectar, pepper and salt.